Friday

September 7, 1979

Part V

Department of

Energy

W'1'ater Heater; Final Rule Amending Test

Procedures

EE-RM-94-230 COMMENT 49N

Friday 

September 7, 1979 

Part V 

Department of 

Energy 

\".'ater Heaters; Anal Rufe Amending Test 

Procedures 
52632 Federal Register / Vol. 44, No. 175 / Friday, September 7, 1979 / Rules and Regulations

DEPARTMENT OF ENERGY hour. Recovery rate was a measure of This measure, sometimes referred to as the rate at which a water heater could "recovery capacity," accounted for the

10 CFR Part 430 heat water. Both of these measures were combined effect of a water heater's

included in the original proposed test power input and recovery efficiency on Energy Conservation Program for procedures because they were likely to the rate at which the water heater could

Consumer Products; Fenal Rulemaking assist consumers in making purchasing heat water. In the proposed test

Amending Test Procedures for Water decisions, procedures, recovery rate was to be

Heaters At the public hearing on the original determined independently of hot water

AOENCY: Department of Energy. proposed water heater test procedures, supply rating and was intended to serve

ACTION: Final rule. members of the water heater industry as a useful measure of the rate at which

argued that, because of the way the term a water heater could recover from a

SUMMARY: The Department of Energy "basic model" was defined, the test large hot water draw.

amends its test procedures for water procedures as proposed were unduly Revising the definition of a water

heaters to specify a new measure of burdensome for the testing of electric heater basic model also made the

water heater capacity, first hour rating. water heaters with immersed heating proposed method for the determination

These test procedures are a part of the elements. The proposed definition of recovery rate unworkable. Again.

energy conservation program for would have required the testing of a lacking a proven recovery rate

consumer products established pursuant large number of models. calculation method and the test data

to the Energy Policy and Conservation After reviewing those comments, a from which to attempt to develop such a

Act, as amended by the National Energy decision was made to revise the method, this proposed measure, like hot

Conservation Policy Act, which requires definition of a water heater basic model water supply rating, had to be deleted

that standard methods of testing be for the final test procedures to exclude from the final test procedures.

prescribed for covered products. immersed heating elements from The investigation into methods for the

EFFECTIVE DATE: October 9, 1979. consideration as a distinguishing feature prediction of hot water supply rating

of a basic model. This revision of the and recovery rate for the determination FOR FURTHER INFORMATION CONTACT: definition of a water heater basic model of some other measure of hot water

James A. Smith, U.S. Department of Energy, solved the burdensome issue but made delivery performance for water heaters

Office of Conservation and Solar the proposed method for the was concluded by DOE at about the

Applications. >Mail Station 2221C. 20 determination of hot water supply rating same time that two events occurred

Massachusetts Avenme. N.W.. Washington. unworkable. which reaffirmed the need for such

Robert .Rot M. Musslet, 0. Musser2 U.S. S.Depar2tment Department of1. of Since hot water supply rating was a measures to be included in the test

Energy. Office of General Counsel. Mail useful measure of the capacity of a procedures for water heaters. The first

Station 3224, 20 Massachusetts Avenue, water heater. members of the water of these events was the release of the

N.W.. Washington. D.C. 205A5. 202-376- heater industry expressed concern over Federal Trade Commission's (FTC) final

4100. the possible loss of this measure. They staff report on FTC's proposed rule

SUPPLEMENTARY INFORMATION:commented that the hot water supply concerning disclosure of energy cost and

*LEA Nrating of an electric water heater with consumption information in labeling and

A. Background immersed heating elements could be advertising of consumer products. This

Title 11. Part B of the Energy Policy predicted by calculation: however, they report was released on February 12,

iand Conservation Act (Act) (Pub. L. 94 had no such calculation method to 1979. In it. FI'C made the following

163) estahlished an energy conservation present at the time, nor did they submit statement in the section dealing with the

program for consumer products. As part any data from which a hot water supply determination of the capacity of

of this program. section 323 (42 U.S.C. rating calculation method might be consumer products covered by the

6293) of the Act requires that standard develop d. proposed rule: While the development of a method p methods of testing to determinefor predicting the hot water supply"Historically, gas and oil water heater

estimated annual operating cost and at rating of such a water heater was sales are based on recovery capacity, while

least one other useful measure of energy consided feasible, it was found that, electric water heater comparisons are based

consumption be prescribed for certain considered feasibe twasfoundthatcapacity. Some participants lin the

products, including water heaters. lacking a proven hot water supply rating public hearing and written commentsl argued

Test procedures for water heaters calculation method and test data from that the traditional methods of comparing

were proposed by notice issued April 21. which to attempt to develop such a water heaters are unsatisfactory. A system

7 e4 pro 2 t April 7 27 method, the proposed measure, hot that reflects the energy needed both to store 1977 (42 FR 2157o. April 27. 1977).r inal water supply rating, had to be deleted and to replace consumed hot water is more test procedures for water heaters were from tes pr test t procedures for water informative than one that measures only

prescibed on September 27 1977 (42 FR heaters. towever, a statement was storage or recovery. The Recommended Rule

54110, October 4. 1977). DOE amended included in the notice of the final rule on reservedly bases capacity on tank storage, in

the test procedures for water heaters by test procedures to the effect that further accordance with current DOE test

notice issued October 13, 19,78 (43 FR itest procedures to the effect fth h e r rocedures. If the Department of Energy 488notice issued October 13.197,3 FR investigations into methods for the prescribes method, of measuring first hour

489-R. October 19, 1978) in order to calculation of hot water supply rating or recovery rates or hot water supply ralings

specify a new method of determining the for the determination of some other before the Commission issues the final measure of efficiency of water heaters. measure of hot water delivery labeling rule, staff recommends that the final

When originally proposed on April 21, performance for water heaters would be rule refect the DOE procedure for measuring 1977. the test procedures for water made. It was further stated that the capacity in effect at that time."

hears included t measure of hot water heater industry and other The second event was the series of six water supply rating and recovery rate. interested parties were invited to public meetings held on DOE's

Hot wlter supply rating was a measure participate in these investigations. advanced notice of proposed rulemaling of the m.ximum amount of hot water No comments on the original proposed regarding energy efficiency standards

that a water heater could provide in one test procedures for water heaters for nine types of consumer products.

addressed the measure of recovery rate. These public meetings were held over

EE-RM-94-230 COMMENT 49N

52632 Federal Register / Vol. 44. No. 175 / Friday. September 7. 1979 / Rules and Rel!ulations 

DEPARTMENT OF ENERGY 

10 CFR Part 430 

Energy ConseNaUon Program for 

Consumer Products; Final Rulemaklng 

Amending Test Procedures for Water 

Heaters 

AGENCY: Depurtment of Energy. 

ACTION: Final rule. 

SUMMARY: The Department of Energy 

amends its te~t procedures ror water 

heaters to specify a new meusure of 

water heater capacity. first hour rating. 

These test procedures are a part of the 

ener~y conservation prGgram for 

consumer products established pursuant 

to the Energy Policy and Conservation 

Act. as amended by the Neltional Energy 

Conservation Policy Act. which requires 

that standArd methods of testing be 

prescribed for covered products. 

EFFECTIVE DATI!: October 9. 1979. 

FOR FURTHER tNFORMATION CONTACT: 

James A. Smith. U.S. Department of Energy. 

Ofiice of Conservation and Solar 

Applicatiol!s. Mail Station 2221C. 20 

Massachusetts Avemle. N.W .. Washington. 

D.C. 20585. :mZ-.17~14. 

Robert M. Mussier. U.S. Departmr.nt of 

En"rIlY. Offier. of Generul Cuunsel. Muil 

Stillion 3224. 20 Mus901chusett. Avenue. 

N. W .. W~shingron. D.C. 205115. 202-J~!>-

4100. 

SUPPLEMENT ARY INFORMATION: 

A. Background 

Title Ill. Part R of the Energy Policy 

lind Conservdtion ;\ct (Act) (pub. L.94-

1113) estllhliah/!d an enl'rgy conservation 

progrnm for consumer products. A~ part 

of this program. section 323 (42 U.S.C. 

029:1) of tne Act requires that stand.::rd 

methods of testing to determine 

estimated unnuul operating cost and at 

least one .other useful measure of en erg. v 

consumption be prescribed for certain 

products. includin~ w.lter heaten. 

Test procedures for water heaters 

were proposed by notice issued April 21; 

1977 (42 FR 21576. April 27. 1977). Final 

test procedures for wHter h<!aters were 

prescribed on Sepl'!mber 27.1977 (42 FR 

54110. October 4. 1977). DOE amended 

thp. test procedures for water heaters by 

notice issued Odob~r 13. 19:"8 (43 FR 

48966. October 19. 1978) in order to 

~_pecify a new method of determining the 

mp.aSllre of efficiency of water heaters. 

Whp.n originally proposed on I\pril21. 

1977. the lest proceoures for ...... ilter 

hr.a:ers included the measure~ of hot 

watcr supply ralin!! and recovt.ry rate. 

Hot willer supply rating W/l8 a measure 

of the mll~imum umount (If hot wllter 

thlll a wllter hellIer could provide in olle 

hour. Recovery rate was a measure of 

the rate at which a water heater could 

heat water. Doth of these measures were 

included in the original proposed test 

procedures because they were likely to 

assist consumers in making purchasing 

decisions. 

At the public hearing on the original 

proposed water heater test procedures. 

members of the watpr heater industry 

argued that. because of the way the term 

"basic model"was defined. the test 

procedures as proposed were unduly 

burdensome for the testing of electric 

water heaters with immersed hellting 

elements. The proposed definition 

would have required the testing of a 

Iilrge number of models. 

Arter reviewing those commellts. a 

decision was made to revise the 

delinition of a water heater basiC model 

for the finalte,t procedures to exclude 

immersed heating elements from 

consideration as a distinguishing feature 

of a basic model. This revision of the 

definition of a water heater basic model 

solved the burdensome issue but made 

the proposed method ror the 

determination of hot water supply rating 

unworkable. 

Since hot water supply rating was a 

useful measure of the capacity of a 

water heater. members of the water 

heater industry expressed concern over 

the possible loss of this measure. They 

commented that the hot water supply 

rating or an electric water heater with 

immersed heating elements could be 

predicted by calculati'on: however. they 

had no such calculntion method to 

present at the time. nor did they submit 

any data from which a hot water supply 

rating calculation method might be 

developed. 

While the development or a method 

ror predicting the hot water supply 

rating of such a waler heater was 

considerC!J feasible. it was round that. 

lacking a proven hot water supply rating 

calculation method and test data rrom 

which to allp.mpt to develop sl!ch a 

method. the proposed measure. hot 

water suppiy rnling. had to be deleted 

rrom the final test procedures for water 

heilters. However. Q stlltement was 

included in the noti..:e or the final rule on 

test procedures to the errect thllt further 

investigations into methods for tile 

calculation of hot water supply rating or 

for the JetHmination of some other 

mea~ure of hot water delivery 

performance for water heaters would be 

made. It was further stated that the 

water heater industry and other 

intr.rcsted parlies were invited to 

participate in these investi$!otions. 

No cumments on t!le original proposed 

test procedures for wllter healers 

Addressed the measure of recovery rate. 

This measure. sometimes referred to as 

"recovery capacity." acco::nted for the 

combined effect of a water heater'S 

power input and recovery effiCiency on 

the rate at which the water heater could 

heat water. In the proposed test 

procedures. recovery rate was to be 

determined independently of hot water 

supply rating and was intended to serve 

as a useful measure of the rate at which 

a water heater could recover from a 

large hot water draw. 

Revising the definition of a water 

heater basic model also made the 

proposed method for the determination 

of recovery rate unworkable. Again. 

lacking a proven recovery rate 

calculation method and the test data 

from which to attempt to develop such a 

method. this proposed measure. like hot 

water supply rating. had to be deleted 

from the final test procedures. 

The investigation into methods for the 

prediction of hot water supply rating 

and recovery rate for the determination 

of some other measure of hot water 

delivery perrormance ror water heaters 

was concluded by DOE at about the 

8ame time that two events occurred 

which reaffirmed the need ror such 

measures to be included in the test 

procedures for water heaters. The first 

of these events was the release of the 

Federal Trade Commi~sion's (FTC) final 

starf report on FTC's proposed rule 

concerning disclosure or energy cost and 

consumption information in labeling and 

advertising of consumer products, This 

report was r!'lp.ased on February 12. 

1979. In it. Jo-rc mnde the following 

statement in the section dealing with the 

determination of the capacity or 

consumer products covered by the 

proposed rule: 

"Historically. gas and oil water heater 

sales are based on recovery capacity. while 

electric water heater compHrison. are bHsed on 8tor~ge capacity. Some participanls lin the 

public hearing and ",riUen commentsl argued 

that the traditional methods of compilring 

water heaters are uns·utisfactory. A syslem 

that renects the energy needed bOlh to store 

and to replHcc consumed hot water is more 

informative thRn one thllt measures onlv 

storage or recovery. The Recommended- Rule 

reservedly ba~es capacity on tank slorage. in 

accordance with current DOE test 

procedure9. If thp. Dpparfml'nt of EnH~v 

prescribes mprhod. nf m~"9urinl! firsl liour 

recovery r81~9 or hoI Willer supply rolings 

before ine Commission issues the final 

labclinl! rule. staff recommends that the final 

rule reflect the DOE procedure for mea.uring 

capacity in eff~,;t at that lime." 

The second event was the series of six 

public meetin$!~ held on DOE's 

advllnr:ed notice of propo~ed rlllem"~inR 

regarding energy effidcncy stunJards 

for nine typc9 of consumer products. 

These public meetings were held O\'er 
Federal Register / Vol. 44. Nr. 175 / Friday. September 7. 1979 / Rules and Regulations 52633

the period January 26 to February 8. maintain hour after hour. The proposed consumers would usually be able to

1979. Four of the participants in these method for determining first hour rating make meaningful comparisons between

public meetings. all representatives of differed from that originally proposed water heaters of like energy source on

the water heater industry. made for determining hot water supply rating. the basis of storage capacity. they

sl.trrements to the effect that DOE should Hot water supply rating was to be pointed out that meaningful use first hour rating as the measure of determined entirely by test. First hour comparisons could not be made

the capacity of a water heater and issue rating. as proposed. was to be between water heaters of different

rcir:::;urn energy efficiency standards determined partially by test and energy sources based on storage.

which are a function of this capacity partially by calculation. This new capacity alone. The basis for the ' rrnisure. (As it is used here, first hour method for determining the measure commenters' remarks concerns the

r.tinii can be considered to be was intended to reduce the test burden contribution of a water heater's

equiv:alent to hot water supply rating.) without sacrificing accuracy. recovery rate to its hot water delivery .lhiusl corn.menters claimed that the A public hearing on the proposed performance. Typically, for water

irtalblishniern of un energy efficiency amendment was held on June 27.1979. heaters of like energy source and like

s:.lnatlud bused on a fixed energy factor B. Discussion of Comments storage capacity, recovery rate will not

'.,due for water heaters of a given s vary greatly. Therefore. the contribution

ln.Trgy source would impose a more Three speakers all representatives of oft rcover y of recovery rate to the hot water rate to the hot water

st!inge.t requirement on water heaters the wndttest industrytesified on de performance of water heater 

with lar:g tank volumes than those with the proposed amendment to the test of like energy source may be accounted

s.m;il! !ank volu.mes. Such an approach procedures for water heatersat the for implicitly in the approach taken to

wuuld discriminate against water public hearing. Six written comments "size" a water heater to a given

het l:rs with large tank volumes. It was oncerning the proposed amendment application. However. a different sizing

poinilted out that water heaters with had been received by July 18 1979. Five approach would have to be used for

I.lrge tank volumes provide a utility of the written comments were submitted each water heater energy source since

which cannot always be matched by by representatives of the water heater the contribution of recovery rate to hot

those with smaller tank volumes industry. The sixth was submitted by a water delivery performance will usually

particularly in the case of electric water water heater retailer. Although some of vary greatly between water heaters of these written comments were received heters. Commenters argued thatafter the ose of the written comment like storage capacity but different consumers need electric water heaters aftr wrenergy sources. Typically, an electric

with large tank volumes to satisfy their period on July 9,1979. all were water heater has a much lower recovery hot water in order neds to ake considered in the development of this jhot water needs in order to takef ulrate than a gas water hea.er which, in

advantage of off-peak or time-of-day Thfoowing discssion the turn. typically has a much lower

electric utility rates to reduce theirs ise in esti esented recovery rate than an oil water heater. wa ter heating energy bill. at he pubic hearing and in the written Thu for a given application, the sizing

By notice issued May 3. 1979 (44 FR comments submitted to the docket. The "pproach that is appropriate for gas 27191. May 9. 1979). DOE. in an effort to comments have been analyzed by topic water heaters may indicate that a unit

develop a more useful measure of water rather than source, since in many cases with a storage capacity of 30 gallons heater capacity. proposed to amend the the same or similar comments were would suffice while the sizing approach

test procedures for water heaters to received from more than one source. that is appropriate for electric water

incorporate two new measures. recovery 1. First hour rating and the Federal heaters may indicate that a unit with a rain and first hour rating. Trade Commission s lubeling rule. All storage capacity of 50 gallons would be

Recovery rate. as proposed. was the commenters expressed the concern that required To present a different sizing same as it appeared in the original DOE was proposing to amend its test approach for each water heater energy

proposed test procedures except that a procedures for water heaters to specify source for the purpose of enabling new method of determining the power a new measure of capacity. first hour consumers to make comparisons

input of an electric water heater with rating. at a time when FTC was between water heaters of different

immersed heating elements was preparing to issue a final rule for the energy sources would complicate the

specified. Also, as proposed. recovery labeling of water heaters which would water heater labels and the consumer

rulte was to be used in the determination require the disclosure of a different education process associated with the

of first hour rating. measure of capacity, storage capacity. labeling program. Using first hour rating.

First hour rating. as proposed. was a This concern prompted most of the valid comparisons may be made

measure conceptually equivalent to hot comments submitted. between water heaters of both like and

water supply rating as it appeared in the Several commenters addressed the unlike energy sources. Adopting first

original proposed test procedures for need for using first hour rating as the hour rating as the measure of the

water heaters. This new name for the measure of the capacity of a water capacity of a water heater would avoid

measure was deemed more descriptive heater. First hour rating was cited as a all of the difficulties described above.

since it both identified the time base of true measure of a water heater's ability Several comments were made to the

the measure. an hour. and by the use of to do work. I.e.. deliver hot water on effect that DOE should not amend the

the term "firt." implied that the demand. end the measure which should test procedures for water heaters to measure was only indicative of the serve as the basis for making meaningful specify the new measure, first hour

performance of the water heater during comparisions between all types of water rating, if FTC prior to issuing its final

its "first" hour of operation. While the heaters. It was remarked that storage labeling rule. is not going to replace consumer will not know the conditions capacity, the only measure of the storage capacity with first hour rating as for the determination of this measure. it capacity of a water heater included in the measure of the capacity of a water

is sufficient that the term will DOE's test procedures at the time, heater. It was argued that such an discourage the Interpretation of the suffices only as a measure of a water amendment to the test procedures for measure as a rate of hot water delivery heater's ability to store water. While water heaters would be pointless if FTC

performance which the water heater can commenters acknowledged that were not to require the disclosure of the

EE-RM-94-230 COMMENT 49N

t'ederalRegistcr I Vol. 44. N('. 175 / FridCly. September 7. 1979 I Rules, and Regulations 52633 

till' period JHnuary 26 to February 8. 

19;'9, f'uur of the participants in these 

public meetings. al\ representatives of 

the water heater industry. made 

sf"tem"nts to t!le effect that DOE should 

use first hour rating as the measure of 

tn!' cap.Jcity of a wHter heater lind issue 

r::ir::mum energy ef!iciency standardu 

which ;Ire a function of trJs capRcity 

m'~d~ure, (.\s :t is used here. first hOUT 

riltins; can ue considered to be 

eqw\':Jlent tohot water supply rating.) 

'nw~,~ commenters r:Iaimed thnt the 

,,,tabbhment of un enerllY eFfici!'ncy ~:.l!llliJrlJ llllseu on iI fixeu energy fuctor 

\.!l1I1! for wiltrJr heaters of a given 

I!!wr;.lY SOl!rce would impose a more 

~t~in:;er.t requirement on waler heaters 

with liI~gl~ tank .olume3 tha.nthose with 

~:nill! lank ;·olumes. Such an approach 

\\'oulddiscriminatc against water 

h,,;tt',r~ with I<lrge tank volumes. It was 

pt>intl,d oct that waler heaters with 

l.q~1! tank .olumes provide a utility 

which cannot alwClYs be matched by 

those with smaller t<lnk\·olum('s. 

particularly in the case of electric wilter 

hl'aters. Commenters argued that 

c'Jnsumers need electric water heaters 

with large tank volumes to satisfy their 

hot wilter needs in order to take 

iI(hanlage of off·peak or time·of·day 

f'll'ctric utility rates to reduce their 

wat~r heating energy bill. 

Dy notice issued May 3. 1979 (44 FR 

Z7191. May 9. 19i9). DOE. in an effort to 

c!!'\'elop a more useful measure of water 

hl'atncapacity. proposed to amend the 

I!~~t procedures for water he'aters to 

incurpornle two new measures. recovery 

rate and first hour rating. 

Recovery raIl'. as proposed. was the 

~ame liS it appeared in the original 

proposed test procedures except that a 

new method of determinill8 the power 

input oC lin electric water heater with 

immerRed healing elements was 

specified. Also. as proposed. recovery 

rllll! Wltl to be used in the determination 

of first hour rating. 

First hour ratiDg. as proposed. was a 

men sure concephl811y equivalent to hot 

wut!'r supply ratill8 as it appeared in the 

originlll proposed test procedure. for 

wnter heaters.'1'his new name for the 

m!'asure WIS deemed more descriptive 

since it both identified the time base of 

the measure. an bour. and by the IDe of 

the term "first." implied that the measure was only indicatiye of the 

performance of the water beater dlll'ing 

its "first': bour of operation. While the 

consumer will not know the conditlonl 

ror the d~'emliJllltion or tru. menure, it 

I, ,uendent that tha term will . discourago the Interpretation of the 

measure as II rale of bot water delivery 

, performance which the water beater can 

muiutain hour ilfter hour. The proposed 

methuJ for determining first hour rating 

diff .. red from that originally proposed 

fur dt~termining hot water supply ratiog. 

Hot waler supply rating was to be 

determined entirely by test. First hour 

rating. 115 proposed. WIIS to be 

determined partially by test and 

partially by calcuhilion. This new 

mel hod for determining the measure 

was intended to reduce the test burden 

without sacrificing'accuracy. 

t\ public hearing on the proposed 

IIrncndmlmt was held on June 27.1979. 

B. Dilfcussion of Comments 

"fhr!!e speakers. all representatives of 

the water heater industry,'testified on 

the proposed amendment to the test 

procedures fur wllter heaters at the 

public hearing. 'Six written comments 

concerning the proposed amendment 

had been received by July 18. 1979. Five 

of the writte:1 comments were submitted 

by rp.presentatives of the water beater 

industry. The sixth was submitted by a 

water heater f(·tailer. Although some of 

these written comments were received 

ilftpr the close of the written comment 

period on July 9. 1979. all were 

considered in the development of this 

. finlll rule. 

The following is a discllssion of the 

issues raised in the testimony presented 

at the public hearing and i.n the written, 

comments submitted to the docket. The 

comments have been analyzed by topic. 

rather than source. since in man)' cases 

the same or similar comments were 

received from more than one source. 1. First hour ratins and the Federal 

Trade Commission's/ube/ing rule. All 

commenters expressed the concern that 

DOE was proposing to amend its test 

procedures for water heaters to specify 

a new measure of capacity, first hour 

rating. at a time when FTC was 

preparill8 to issue a final rule for the 

labeling of water heaters which would 

require the disclosure of Ii different 

measure of capacity. storll8e capacity. 

This concern prompted most Of the 

comments submitted. 

Several commenten addressed the 

need for using first hour rating as the 

measure of the capacity of a water . 

heater. First hour rating was cited as a 

true measure ofa water heater's ability 

to do work. I.e" deliver hot water on demand. end the measure which should serve as the basis for making meaningful 

com paris ions between all types of water 

heaters. It wa. remarked that atcrase 

capacity. the only mea lUre of the 

'capacity of a water heater ineluded in 

DOE's tellt procedures at the time, 

sufficel only a. a measure of a water 

heater'. ability to atore water. While 

cornmenters acknowledsed that 

, consum~rs would uS:JCllly ue able to 

make meaningful comparisons between 

water heaters of like energy source on 

the basis of storage capacity. they 

pointed out that meaningful 

comparisons could not be made 

between water heaters of different 

energy sources based on storage, 

capacity alone. The basis for the' 

commenters' remCirks concerns the 

contribution of a wR'tet heater's 

recoverv rate to its hot water deliverv 

perform'anc{'. Typically. for wa-ter . 

heaters of like !'ne'llY source and like storagl~ r.apllcity. reco\'ery rate will not 

\'ary greally. Therefore. the contribution 

of reCO\'ery rate to the hot ""'ater 

delivery performance of water heaters 

of like energy source may be accounted 

for implicitly in the approach taken to 

"size" a water heaterto a gh'en 

applicntion. However. a diffe",nt ~iz:ng 

approach would have to be used for 

each water heater energy source since 

the contribution of recovery rate to hot 

water deli\'ery performance will usually 

vary greatly between water heaters of 

like storage capacity but different 

enersy sources. Typically. an electric 

water heater has a much lower recovery 

rate than a gas wliter hea.!!r which. in 

tum. typically has a much lower 

recovery rate than an oil water heater. 

Thus for a given application. the sizing 

'\pproach that is appropriate for gas 

water heaters may indicate that a unit 

with a storage capacity of 30 gallons 

would suffice while the sizing approach 

'that is appropriate for electric water' 

heaters may indicate that a unit with a 

storage capacity of SO gallons would be 

required. To presenl a different sizing 

approach for each water beater energy 

source for the purpose of enablina 

consumers to make comparisons 

between water heaters of different 

energy sources would complicate the 

water heater labels and the consumer 

education procell aSsociated with the 

labelill8 program. Usill8 rarst bour rating. 

valid comparisons may be made 

between water beatel'll of both like and 

unlike energy aourcea. Adopting rarst 

hour rating as the measure of the 

capacity of. water heater would avoid 

all of the difficulties described above. 

Several comments were mIlde to the 

effect that DOE should not ante!ld the 

test procedures for water heaters to 

specify the'new measure, first hour 

ratiftg, If FI'C. prior to issuing its final 

labeling rule, Is not goill8 to replace 

storage capacity with first hour rating as the measure of the capacity or I water 

heater. II wa~ Rrgued that such an 

amendment to the test procedures for 

water heAters would be pointless if fTC 

were not to require the disclosure of the 
52634 Federal Register / Vol. 44. No. 175 / Friday, September 7. 1979 / Rules and Regulations I- I

new measure on the label for water proposed amendment would impose a - heaters. Several cost estimates were heaters. substantial test burden on the water presented for such a retesting program.

Also of concern was the prospect that heater industry. The burden that was of The trade association estimated the cost

FTC might proceed with issuing its final concern was not the incremental to be as high as $18,000 per company.

labeling rule utilizing storage capacity additional test time and cost of One manufacturer estimated labor costs

as the measure of the capacity of a determining first hour rating as part of a at S27,000 and an additional S19.000

water heater and then revise it at some complete test of a water heater in expense to reclaim the test units for

future date in order to require the use of accordance with the existing test sale. Another manufacturer estimated

first hour rating in place of storage procedures. but the burden of having to his test cost at $12,000 and commented

capacity. It was argued that such a test a water heater solely to determine that his firm would have to build units

switch in the labeling requirement its first hour rating. [n anticipation of expressly for test purposes since his

would disrupt consumereducation FTC's labeling requirement. the water firm manufacturs to order and not to

programs based on the original labels heater manufacturers claimed that they stock. A third manufacturer estimated

and confuse the consumer. During such had already commenced, and to a large his additional test cost would be at least a transition period consumers might extent completed, testing water heaters $10.000.

attempt to make comparisons between in accordance with DOE's test Concern was also expressed over the

water heaters when some might bear a procedures. This testing has been done possibility that, in order to provide more label disclosing storage capacity while in order to be able to supply FTC with time for completing required testing,

the labels on other water heaters might the energy consumption and cost of FTC might delay the labeling rule for

disclose first hour rating. Commenters operation figures which manufacturers water heaters if DOE were to finalize its

also remarked that such a switch would expect FTC to require to be submitted GO test for first hour rating as it was impose additional costs associated with days after the issuance of its final proposed. Commenters projected that a the printing of new labels for'water labeling rule. DOE's proposed delay of the labeling rule for water

heaters. 'Ihese cost would have to be amendment would, if finalized. require heaters would severely complicate the

passed on to consumers. that manufacturers perform the consumer education process regarding

Concern was also expressed over the proposed first hour rating test on all of the use of consumer product labels.

possibility that FTC might delay the the models of water heaters for which The manufacturers commented that

labeling rule for water heaters if DOE the tests for energy consumption and none of these problems which they had

were to finalize its test for first hour cost of operation had been completed. identified concerning DOE's proposal for

ruating as it was proposed. The water The effort and expense of such further determining first hour rating by test

heater industry projected that a delay of testing would impose a burden would be encountered if DOE were to

the labeling rule for water heaters would significantly greater than the burden accept their recommendation that first

.:verely complicate the consumer that would have been sustained had the hour rating be predicted by calculation.

.lducation process regarding the use of tests for first hour rating been performed All of the water heater manufacturers

hhe consumer product labels. at the same time as all other tests. who submitted comments supported this

I.TC staff attended DOE's publicomes e t t recommendation and offered first hour

hearing regarding its proposed Comments were madethat the timin rating calculation formulas. The industry

.imendment to the test procedures for of D rule 's to amend the test trade association did the same. All of

water heaters. Additionally, FTC staff procedures and C's rule to prescribe the proposed formulas followed the

h;,s been provided with copies of aill labels for water heaters would impose same approach toward calculating first

submissions to the docket regarding this an unreasonable test burden. If DOEhour rating. H oward calculating first pnposed rulemaking. DOE ad FTC were to issue its final rule to amend the hour rating. However there were some proposeld rulcmiking. DOE, and FTC w er o ue ts n l u e t

o am edetail differences which would cause staff h~ave discussed the issues raised in test procedures f

o r water heaters as it slight differences in the calculated -.

te.stimony at the public hearing and in d a in time for FTC to alues.

,submissions to the docket which revise its rule prescribing labels for All but one water heater manufacturer

.. ncern the FTC labeling program. FTC water heaters, the water heater industry offered data in support of their *

luiff has indicated that they continue to could have as little as 60 days in which suggested first hour rating calculation

support their recommendation to the to accomplish all testing in order to be formulas. The data submitted compared ,:.'.lderal Trade) Commission that the able to present the test results to FTC on the results of determining first hour

final labeling rule for water heaters time. rating by test with the results of using

should reflect the DOE procedure for While some manufacturers said thai it the commenter's suggested calculation

:,:.isuring water heater capacity in would be possible for them to meet such formula. The results showed general

,*ffect at the time that the labeling rule is a requirement should it be imposed. a agreement between the results

issued. Following these discussions. trade association for members of the determined by calculation and those

DIOE staff resolved to issue a final rule water heater industry expressed determined by test. In most cases the

to amend its test procedures for water concern for other manufacturers.. calculated value differed from the test

heaters in time t6 permit FTC to adopt particularly those with limited test value by less than three percent. first hour rating in place of storage facilities or none at all. The trade Several of the water heater · capacity as the measure of the capacity association'claimed that water heater manufacturers and the trade association

of a water heater and issue its final manufacturers would need six months to acknowledged that there may be some

labeling rule with no delay in schedule. conduct the tests once they were designs of water heaters for which their

The timing of today's issuance has been published. suggested formula would yield overly coordinated with FrC staff to assure It was further remarked that such a conservative results, i.e.. up to ten

avoidance of the potential problems test requirement would not only impose percent below the value that would be

discussed above. significant test costs which would be determined using the proposed first hour

Z. The ;urden of testing and npethoids paissed on to consumers. but it would rating test. These would be the designs for fIetrirmining, first hour rotfi,. All of also divert manpower and resources which do an extraordinary job of

the water heater manufacturers who from product development work on new limiting mixing of hot and cold water in

submitted comments claimed that the energy efficient designs of water the tank during a water draw. To avoid

EE-RM-94-230 COMMENT 49N

52634 Federal Register I Vol. 44. No. 175 I Friday, September 7. '1979 I Rules and Regulations 7 

new measure on the label for water 

heuters. . 

Also of concern was the prospect that 

r~rc might proceed with issuing its final 

labeli:1g rule utilizing storage capacity 

as the measure of the capacity of a . 

water heater and then revise it at some 

future date in order to require the use of 

fint hour rating in place of storage 

capacity. It was argued that such a 

switch in the labeling requirement 

would disrupt consumereduca tion 

programs based on the originallilbels 

and confuse thn consumer. Durin!! ~uGh 

II tran~ition period consumer~ mi)lht 

attempt to make comparisons between 

water he;;ters wh.m some might bea:' a 

. label disclosing ~torage capar:ity while 

the labels on other water heaters might 

disclose first hour rating. Commenters 

also remarked that such a switch would 

impose ;;dditional costs associa led with 

the prin1inf; of new labels for'water 

hpaters. These cost would have to be 

passed on to consumers. 

Concern was also expressed over the 

possibility that FTC might delay the 

labeling rule for water heaters if DOE 

. wcre to finalize its test for first hour 

"aling as it was proposed. The water 

hcater industry projeGted that a delay of 

the laheling rule for water heaters would 

"!verely complicate the consumer 

,·duclltion process regarding the use of 

Ih,~ consumer product labels: 

I-TC staff Ill1ended DOE's public 

hl!aring regarding its proposed 

.. mendment to the test procedures for 

water heaters. Additionally. FTC staff 

hilS heen provided with copies of nil ""bmis~ions tl' the docket rej:l/lrding this . prnpOSI!d rulemllkinJ;:. DOE alld FTC 

staff h17ve discussed the issues raised in 

t .. stimony at the public hearin)! and in 

"'lbmissions 'to the dockct which 

r.llnr:ern the FTC labelin)! progmm. FTC 

<taff has indicatrd that they continue to 

""pport their r:!commendation to the 

'Fl'dernl Trade) Commi~sion that thl! 

fillilllilbeling rule for water hellters 

,hould renect the DOE procedure for 

l,l'!,\Suring water hrlltN cllp;;city in 

"ffectat the time th;;t the labeling rule is 

l~st7l'd. Following these discussions. 

(JOE stnff resolved to issue a final rule 

. to IPmend ita test procedures ror water 

hl!utl!rs in time to permit FTC to adopt 

first hour rlltin)! in place or stornge 

r.IlPlPcity 1P9 the meRsure of the capacity 

of II water heAter And issue its finnl 

lah!!lin!! rule with no dl'lay in schedule. 

The timing of today's issuance has been 

coordinIPtf)d with FTC staff to assure 

a\'oidllnce of the potential problems 

di!7r.us!7ed above. 

Z. The .iurriell of teslillg alld 1I1"'lhnd.~ 

(or r/,·lt.·rmining first hUllr rolin.I/. All of 

thl' wllter heilter manufacturers who 

suhmitted commenls claiml'd thaI the 

proposed amendment would impose a 

substantial test burden on the water 

heater industry. Thl! burden that was of 

concern was not the incremental 

additional test time and cost of 

determining first hour rating as part of II 

complete test of a water heater in 

accordance with the e"<isting test 

procedures. but the burden of ha ving to 

testa water heater solely to determine 

its first hour ra ting. In an ticipa tion of 

FTC's labeling requirement. the water 

he;;ter manufacturers claimed that Ihey 

had already commenced. and to a la!,!!e 

extent completed, tcsting wuter heaters 

in accordance with DOE's test 

procedures. This testing has bl!!!n done 

in order to be able to s'upply FTC with 

the energy constimption and cost of 

operation figures which manufacturers 

expect FTC to require to be submitted 00 

days after the issuance of its final 

labeling rule. DOE's proposed 

amelldment would. if fimllized. require 

thai manufacturers perform the 

proposed first hour rating test on all of 

the models of water heaters for which 

. the tests for energy consumption and 

cost of operation had been completed. 

The effort and expense of such ·further 

testing would impose a' burden 

signifir.antly greater than the burden 

that would have been sustained had the 

tl!sts for first hour rating been performed 

at the same time as all other tests. 

Comments were made thaI the timing 

of DOE's rule to amend the test 

procedures and FTC's rule to prescribe 

labels for water heaters would impose 

lin unreasonable test burden. If DOE 

WI!re to issue its finlll rule to amend the 

test procedures for water heaters us it 

was proposed and in time for FTC to 

revise its rule prescribing labels for 

water heaters. the water heater industry 

could have liS little liS 60 days' in which 

to accomplish all testing in order to be 

;;ble to presenl the test results to FTC on 

time. 

. While some manufacturl'rs said that it 

would be possible for them to meet such 

a requiwment should .it be. imposed. a 

trade association for members of the 

water heater industry expressed 

concern for oliler manufacturers, . 

particularly those with limited test 

facilities or none at all. The trade 

association'claimed thilt water heater 

manufacturers would need six months to 

conduct the tests once they were 

published. 

It was furthl!r remilrked that such a 

test requirement would not only impose 

sillnificunt test costs which would be 

pm7sed on to consumers. but it would 

also divert mllnpower and resources 

from product development work on new 

, energy efficient designs of water 

heaters. Several cost estimates were 

presented for such a retesting program. 

The trade association estimated the cost 

to be as high as $18.000 per company. 

One manufacturer estimated labor costs 

at S27.000 and an additionlll S19.000 

expense to reclaim the test units for 

sale. Another manufacturer estimated 

his test cost at $12,000 and commented 

that his firm would have to build units 

expressly for test purposes since his 

firm manufacturs to order and not to 

stock .. A third manufacturer estimated 

his additional test cost would be lit least 

SIO.OOO. . 

Concern was also expressed over tht· 

possibility that. in order to provide more 

time for completing required testing, 

FTC might delay the labeling rule for 

water heaters if DOE were \0 finalize its 

test for first hour rating as it was 

proposed. Commenters projected thaI iI 

delay of the labeling rule for water 

heaters would severely complicate the 

consumer education process regardin!! 

the use of consumer product labels. 

The manufacturers commented that 

none of these problems whir:h they had 

idel\tified concerning DOE's proposal for ! 

determining first hour rating by test 

w01,Pld be encountered if DOE were to 

accept their recommendation that first 

hour rating be predicted by clilculation. 

All of the water heater manufacturers 

who submitted comments supported this 

recomr.lendalion and offered first hour 

rating calculation formulas. The industry 

trade association did the same. All of 

the proposed formulas followed the 

same appro;;ch toward clllculating first 

hour rating. However. there were sornp 

detllil differences which would cnuse 

slight differences in the calculated 

values, 

All but one water heater manufacturer 

offered data in support of their 

suggested first hour rating calculation 

formulas. The dala submitted compared 

the results of determining first hour 

mting by test with the results of usin~ 

the com menter's suggested calr:ulation 

formula. The results showed general 

agreement between the results 

determined by calculation lind those 

determined by lest.ln most cases the 

calculated value differed from the test 

value by less thon three percent. 

Several of the water heater 

manufacturers and the trade association 

acknowledged that there may be some 

designs of water heaters for which their 

suggested formula would yield overly 

conservative results, i.e .. up to ten 

percent below the value thllt would be 

determined using the proposed first hour 

rating test. These would be the desisms 

which do an extrllordinary job of . 

limiting mixing of hal and r.o!d water in 

the tank during a water dmw. To avoid 
Federal Register / Vol. 44. No. 175 / Friday. September 7, 1979 / Rules and Regulations 52635

underestimating the first hour rating of a which yields a result which tends to be recommended test method may differ

water heater of such innovative design. slightly lower than that which can be from those obtained using the proposed

it was suggested that water heater obtained by testing. DOE has provided method, this difference will be small in

manufacturers be provided the option of an incentive for manufacturers to comparison to the magnitude of the

conducting a test to determine the first perform the first hour rating test if they results. Moreover, the proposed test

hour rating of such a water heater. have access to test facilities and if, in method is a significantly less

DOE finds that data submitted by the their own judgment, the benefit of a burdensome test than that

water heater industry and data slightly higher first hour rating justifies recommended by the commenter. DOE

generated by the National Bureau of the cost of testing. rejects the commenter's

Standards substantiate that first hour It is also the intent of these provisions recommendation on these grounds.

rating can be calculated for water to insure that first hour rating for all The same commenter who

heaters of conventional design with a new basic models of water heaters shall recommended that the previously

small sacrifice in accuracy over the be determined exclusively by test since proposed hot water supply rating test be

proposed test method. DOE concurs DOE does not find that the prescribed' used to determine first hour rating also

with comments that a formula for test is burdensome when it is conducted offered an alternative to this

calculating first hour rating may yield as part of a complete test of a water recommendation. The suggested

overly conservative results for water heater in accordance with the test alternative was to modify the proposed

heaters of innovative design. DOE:also procedures for water heaters. approach for calculating the

finds that the test burden that would be Should-it become clear at sometime contribution of recovery rate to the first

imposed at this time on water heater that the date by which FTC will require hour rating measure, i.e., the amount of

manufacturers by the proposed rule manufacturers to submit energy water that a water heater can heat and

outweighs the benefits of requiring first consumption and cost of operation make available over the one hour time

hour rating for water heaters to be figures. including first hour ratings, for base of the first hour rating measure.

determined exclusively by test when water heaters will be later than The commenter's position was that the

first hour rating can be calculated with November 30. 1979, DOE will consider time period for this calculation should

only a slight sacrifice in accuracy in extending this termination date of its be one hour minus the time duration

most cases. Further, DOE agrees that the option for allowing first hour rating to be from the start of the water draw to the

alternative of FTC granting relief to calculated or determied bytest. time that the main burner or heating 3; Determining First Hour Rating by water heater manufacturers by delaytinging First Hour atinS element begins operating rather than the

the issuance-of the final labeling rule for Fu versus prtil testing. For time period of one hour minus the time

water heaters to allow sufficient time for determining the first hour rating of a duration of the water draw itelf. The

testing water heaters to determine first water heater by testing, one commenter commenter remarked that !'he main

hour rating could be accompanied by remarked that the proposed test method burnerof a gas water heater would

some confusion among consumers. In which required only one water draw ignite within fifty seconds to two

addition, the slight gain in the accuracy was far better than the test method minutes after the start of the water draw

of the measure disclosed on the label previusl prpsed for determinin the while the water draw itself will last previously proposed for determining the heweraw itself wi l las t that is determined by test rather than by conceptually equivalent measure. hot several minutes longer. It was claimed

calculation does not outweigh the water supply rating, which allowed for that this shortcoming of DOE's proposed adverse Impact of denying useful more than one water draw. Another approach would result in an error of five

Information to consumers making water commenter remarked exactly the gallons in the first hour rating of one of

heater purchasing decisions for a period opposite. This dissenting commenter the commenter's water heaters. The

of time equal to any delay. claimed that by providing'for only one trade association echoed this

Bused on these findings. DOE has water draw to be made the proposed commenter's position that for

modified the requirement of its proposed test method would discriminate against determining first hour rating. the

rule to allow first hour rating to be the best water heaters on the market. contribution of recovery rate should be

calculated or determined by test, at the i.e.. those with both high recovery calculated over the period of time of one manufacturer's option for the period of efficiencies and power input to storage hour minus the time duration of the

time beginning on the effective date of capacity ratios. The commenter water draw until the main burner or today's rule and ending on November remarked that such water heaters could heating element begins operating.

30. 1979. Beginning December 1. 1979. recover from the initial water draw. i.e.. Concerning the recommendation that,

manufacturers will be required to achieve another thermostat cutout for the proposed test method, the

determine first hour rating exclusively within the one hour period that is the contribution of recovery rate should be

by test. The formula for calculating first time base of the first hour rating calculated over the period of time of one hour rating prescribed by today's rule measure. It was claimed that the test hour minus the time duration of the

was developed with the intent that it method for determining first hour rating water draw until the main burner or would yield results which would be previously proposed would, by allowing heating element begins operating. DOE

equal to or slightly less than the results for additional water draws over the one finds that this could lead to "double

which would be obtained by testing. hour period-of the test; yield a better accounting" of hot water. For some The primary intent of these provisions: measure of first hour rating than the water heaters, notably electric water

is to enable manufacturers to supply lower result that would be obtained heaters and gas water heaters with low

FTC with first hour ratings for all with the proposed test method. power input to storage capacity ratios,

existing models of water heaters, either ' DOE has considered the commenter's operation of the heating elements or by testing or by calculation. within a 60 recommendation that DOE adopt the main burner during the water draw test

day period following September 20. previously proposed test method for has little effect on the amount of water

1979. the latest date that FTC currently determining hot water supply rating as withdrawn from the water heater. In

projects for the issuance of its final the test method for determining first other words, nearly the same amount of

labeling rule. However, by prescribing a hour rating. DOE finds that while the water could be withdrawn from the

formula for calculating first hour rating results obtained using the commenter's water heater during the test even if the

, EE-RM-94-230 COMMENT 49N

Federal Register I Vol. 44, No. 175 I Friday. September 7. 1979 I Rl,1les and Regulations 52635 

underestimating the first hour rating of a 

water heater of such innovative design, 

it was suggested that water heater 

manuracturers be provided the option of 

conducting a test to determine the. fint' 

hour rating of such a water heater. 

DOE finds that data submitted by the 

water hellier industry and data 

generated by ihe National Bureau of . 

Standards substantiate that first hour 

rating can be cillculated for water 

heaters of conventional design with a 

small sacrifice in accuracy over the 

proposed test method. DOE concurs 

with comments that a'formulll for 

calculating first hour rating may yield 

.overly conservative results for water 

heaters of il')novative design. DOE:also 

finds that the test burden that would be 

imposed at this time on water heater 

manufacturers by theproposE'd rule 

outweighs the benefits of requiring first 

hour ratinS! for water heaters to be 

detem.ined exclusively by test when 

first hour rating can be calculated with 

only a slight sacrifice in accuracy in 

most. cases. Further. DOE agrees that.the 

alternative of FiC granting relief to 

water heater manufacturers by delaying 

the issuance'of the final labeling rule for. 

water heaters to allow sufficient time for 

testing water heaters to determine first 

hour rating could be accompanied by 

some confu!iion among consumers. In 

addition, the slight gain in the accuracy 

of the measure disclosed on the label 

that is determined by test rather than by 

calculation does not outweigh the 

adverse. impact or denying useful 

Information to consumers making waier 

heater purchasing decisions for a period 

of time equillto any delay. 

Bused on these findings. DOE has 

modified the requirement of its proposed 

rule to allow first hour rating to be ' 

calculated.or determined by test. at the 

manufacturer's option for the period of 

time beginning on .the erre!=live date of 

today's rule and ending on November 

30, 19'79. Be!!inning December 1. 1979. 

manufacturers will be required to 

. determine firsl hour rating exclusii:ely 

by lest. The formul!! for calculating first 

hour raling prescribed by today's rule 

WRS developed with Ihe inlent Ihat if 

would yield results which would be 

equal 10 or slightly less Ihan the results 

which would be obtained by te~ting. 

The primary intent of these provisions 

is to enable manufacturers 10 supply 

Fie with first hour ratings for all 

elCisting models of water heaters. either 

hy tesling or by calculation, within a 60 

day period following September 20. 

1979. the latell! date that Fie currently 

projects for the issuance of its flnol 

labeling rule. However. by prescribing a 

rormula for calculating fir~t hour rating 

which yields a result which tends to be 

slightly lower thlln that which can be 

obtained by testing, DOE has provided 

an incentive for manufacturers to 

perform the firBt hour rating test if they 

have access to test facilities and if. in 

their own judgment, the benefit of B 

slightly higher first hour rating justifies 

the cost of testing. 

It is also the intent of these provisions 

to i,nsure that first hour rating for all 

new basic models of water heaters shall 

be determined exclusively by !cstsince 

DOE does not find that the prescribed' 

test is burdensome when it is conducted 

as part of a complete tesl of 8. water 

heater in accordance with the test 

procedures ror water heaters. 

Should·it become clear at some' time 

that the date by which FiC wi!! require 

manufacturers to submit energy 

. consumption' and cost or operation 

figures, including first hour ratings. for 

waler heaters will be later Ihan 

November 30.1979. POE will consider 

,extending this termination date of its 

option for allowing first hour rating 10 be 

calculated or determined by test. 

3; Determining First Hour Rating bj· 

Testing. 

a. Full versus partia/lesting. For 

determining the first hour rating of a 

'water heater by testing. one commenter 

remarked that the proposed lest melhod 

which required only one water draw. 

was far better than the test method 

previously proposed for determining the 

conceptually equivalent measure. hot 

water supply rating. which allowed for 

more than one wilter draw; Another 

commenler remarked exactly the 

opposite. This dissenting commenter 

claimed that by providing'ior only one 

waler draw to be made.the proposed· 

test method would discriminate against 

tite best waler heaters on the markel .. 

i.e .. those with bolh high recovery' 

efficiencies and power input to slorage 

capacily ratios. The commenter 

remarked Ihal such water healers could 

recover from Ihe Initial waler draw. i.e .. 

achieve another Ihermostat cutoul, 

within the one hour period that is the 

. Iime base of the first hour ratiJJ,2 

measure. It was claimed thaI the tesl 

method for determining first hour rating 

previously proposed would. by allowing 

for addilionalwater draws over the one hour pericid·of the test; yield a better 

• measure of first hour rating than the 

lower. result that ,would be obtained 

with Ihe proposed test method. . DOE has considered Ihe commenter's 

recommendation thill DOE adopt the 

previously proposed test method for 

determining hot waler supply rating as 

the test method for determining first 

hour rating. DOE finds thaI while the 

results obta.ined using the commenter's 

recommended test method may differ 

from those obtained using the proposed 

method. this. difference will be small in 

comparison to the magnitude of the 

results. Moreover, the proposed test 

method is a significantly less 

burdensome test than that 

recommended by tbecommenter. DOE 

rejects the commenter's . 

recommendation on these grounds. 

The satr.! commenter who 

recommended that the preViously 

proposed hot water supply rating tesl be 

used to determine first hour rating also 

offered an alternative to this . 

recommel\dation. The suggesled 

alternative was to modif}' the proposed 

approach for calculating the . 

contribution of recovery rate to the fll'St 

hour rating measure. i.e .• the amount of 

waler thaI a waler heater can heat and 

make available over Ihe one hour time 

base of the first hour rating measure. 

The commenter's position.wa~ that the 

time period for Ihis calculation should 

be one hour minus the time duration 

from the start of the waler draw to the 

time that the. main burner or heating 

elementbegirrs operating rather than the 

time period of one hour minus the time 

. : duration of the waler draw ih,elf. The 

commenter remarked Ihat !"te main 

burner of a ga's water heater would 

. ignite within fifty seconds to two 

minutes after the slart of the water draw 

while the water draw itself will last 

, several minutes longer. It was claimed 

that this shortcoming of DOE's proposed . approach would result In an error of five 

gallons in the fint hour raling of one of 

the commenler's walerheaters. The 

trade association echoed this 

cominenter's position that for 

determining first.hour rating, the . 

contribution of recov!!ryrate should be ~ 

calculated over the period of time of one 

hour minus the time duration of the 

water draw until the main burner or 

heatirlg element begins operating. 

Concerning the recommendation Ihal. 

for the proposed lesl method, the 

contribution of rec()veryrate sp'ould be 

calculated over the period of time of one . 

hour minus the time duration of the 

water draw until the main burner or 

heating element beghlJ1 operating. DOE 

finds that this could lead to "double 

accounting" of hot water. For some 

water heaters. nolably electric water 

heaters and gas water healers with low 

power input to storage capacity ratios. 

operation of the heating elements or 

main burner during the.water draw test 

has little effect on the amount of water 

withdrawn from !he water heater. In 

other words: nearly the same amount of 

water could be withdrawn from the 

water heater during the test even if the 
52636 Federal Register / Vol. 44, No. 175 / Friday. September 7, 1979 / Rules and Regulations

heating elements or main burner was draw test of a 40'F outlet water temperature drop specification. By prevented from operating during the temperature drop. Both commenters today's rule, section 3.7 of the test

water draw. However, for other water were concerned that the specified procedures for water heaters specifies

heaters, notably oil water heaters and temperature drop was excessive and 20'F as the temperature drop for the first

gas water heaters with high power input would lead to inflated values of first hour rating water draw test.

to storage capacity ratios, the effect of hour rating for water heaters which, in c. Impact on water heater utility. A

main burner operation has a significant turn. could lead consumers to purchase commenter expressed concern that the

effect on the amount of water that can water heaters of insufficient capacity to proposed first hour rating water draw

be withdrawn. Therefore. some of the satisfy their needs. One commenter test would encourage manufacturers to

water heated by the operation of the remarked that a 20'F temperature drop produce water heaters which do not

main burner during the water draw test specification would be more appropriate maintain a relatively constant outlet

would be accounted for in the amount of for the water draw test in light of water temperature when subjected to a waler withdrawn from the welter heater recommendations being mad,! to water draw. The commenter remarked

during the test. Adoption of the consumers to lower their water heater that. through widely recognized industry comm,-nter's recommendation would thermostats to as low as 120'F. It was standards. the water heater industry has

allow full credit in the calculated claimed that consumers who operate encouraged water heater designs that

recovery rate contribution term for all their water heaters at these can deliver the major portion of a water

water that could be heated by the main recommended thermostat settings will heater's storage capacity at a relatively burner over the period of the water run out of usable hot water well before constant outlet water temperature draw. Thus. some amount of water incurring a 40°F outlet water nearly equal to the initial outlet water

could be accounted for twice, once in temperature drop but in most cases not temperature when subjected to a water the water draw test and again in the before incurring a 20°F outlet draw. The commenter pointed out that

calculated recovery rate contribution temperature drop. the utility of such designs is that

term. resulting in an inflated first hour The commenters are of the opinion consumers can enjoy a relatively rating for such w.ater heaters. DOE that significantly different first hour constant water temperature for personal re(jects the commenters recommendation rating water draw test results will be applications. e.g., bathing and on this basis. but finds that the proposed obtained if instead of specifying 40'F as showering. without having to

method for the determination of first the outlet water temperature drop, a continually adjust the hot and cold

hour rating would discriminate against smaller temperature drop is specified. water flow rates to account for some water heaters by not fully DOE does not share this opinion. DOE fluctuations in the hot water supply a.ccounting for the amount of waier finds that, for current water heater temperature. The commenter remarked hea;ed by the operation of the heating designs. an outlet water temperature that DOE's proposed rule would

elements or main burner of a water drop specification of 40°F will yield adversely affect this utility. By not heater during the water draw test. water draw test results only slightly accounting for the energy associated

Therefore. DOE has modified its greater than those that would be with the water withdrawn from the approach for the determination of first obtained using a 20'F temperature drop water heater, the commenter pointed out

hour rating to insure that all water specification. This is because current that for a given water heater design heaters are treated equally. Dy today's water heater designs inhibit dilution of more favorable results could be rnle. section 3.7 of the test procedures the stored hot water with the incoming obtained with the proposed test if it

for water heaters requires that the water cold water when subjected to a water were possible to modify the design of

draw test be conducted with a!l draw. Thus, when subjected to the water the water heater to cause the outlet electrical power or fuel to the heating draw test. these designs of water water temperature to drop off more elements or main burner interrupted to heaters exhibit a relatively constant quickly during the course of the water

prevent their operation. Section 3.7 outlet water temperature or an outlet draw. It was pointed out that all other

further requires that the elapsed time water temperature which falls off only things being equal. the amount of water

from the start of the test until the first very slowly until most of the hot water that could be withdrawn from a water

thermostat aets to operate the heating his been withdrawn at which time there heater which is capable of maintaining a -rmernits or main burner be recorded. is a rapid drop of more than 40'F. relatively constant outlet water

he contribution of recovery rate to the While DOE does not agree with the temperature will be less than the

first hour rating measure will be commenters' contention. i.e.. that the amount of water that could be

calcu!ated over the period of time of one outlet water temperature drop withdrawn from a water heater which

hour minus this elapsed time. Thus. the specification of the first hour rating induces dilution of the stored hot water

calculated recovery rate contribution water draw test has a significant effect with the incoming cold water (i.e., in

term will account for all of the water on the results of the test. DOE does find such a fashion that the outlet water

that could be heated by a water heater merit in the recommendation that 20'F temperature would fall gradually over the one hour ime base of the first he specified as the outlet water through the temperature drop specified hour rating measure while the results of temperature drop for this test. Should a for the proposed first hour rating water

the water draw test will account for water heater manufacturer introduce a draw test). A greater total volume of

only the contribution of a water heaters new design of water heater which does water could be withdra wn from the

ar.pabilitv to deliver hot w...er from not inhibit dilution of the stored hot water heatcr in the l:;ter case because a storage. Summing these two terms to v.aer with the incoming cold water significant amount of the incoming cold

yvild first hour rating will account for all when subjected to a water draw. water would be wilhdrawn as a result of of the hot water that could possibly be conducting the vwat:r draw test using dilution. In the former case. very little

liuvered by a water hieat oic.rr ranne 't'F as the outlet water temperature cold water would be withdraw:n in

h iur period. drop specification will yield a more addition to the stored hot water

h bWctotr imlra test rtempero.o'r drop. representative first hour rating than that withdrawn. Further. the greater the

Two comments were made concerning which would have been determined had outlet water te-:perature drop specified. the specification in the proposed water 40'F been used os the cutlet water the greater the amount of cold rwater

... . w 

EE-RM-94-230 COMMENT 49N

52636 Federal Register I Vol. 44, No. 175 I Friday, September 7, 1979 I Rules and Regulations 

heating elements or main burner was 

prevented from operating during the 

water draw. However. for other water 

heaters. notably oil water heaters and 

gas water heaters with high power input 

to storuge cilpacity riltios. the effect of 

main burner operation has a significant 

effect on thc amount of water that can 

be withdrawn. Therefore. some of the 

wat(:~ heilted by the operation of the 

main burner during the water draw test 

would be accounted for in the amount of 

WII'er withdruwn from the Wlttcr heater 

ullrin!! thl! te,1. Adoption of the 

cOlT1m':nter's recommendation would 

allow full credit in the calculated 

n'covery rflte contribution term for all 

water that could be heated by the milin 

burner over the period of the water . 

draw. Thus. some amount of water 

could be accounted for twice. once in 

the W'ltl'r draw test ilnd again in the 

ciilc'Jlatr:u recovery rilte contribution 

term. resulting in an inflated first hour 

rating for such ·.\filter heaters. DOE 

rejPcts the commenters recommendation 

on this bilsis. but finch that the proposed 

method fur the detf:rmination of first 

hour rating would discriminate against 

sume water heaters by no~ fully 

ilr.collnlin!! for the amount of waier 

!ow a ted by the operation of the heating 

dements cr main burner of a water 

heater durin)! the water draw tesl. 

Thrrefore. DOE has modificd its 

appro'lch for the detennination of first 

hour rating to insurc that all water 

heaters lire treated equnlly. !Jy today's 

rill". section 3.7 of the test pror.edures 

for water hellters requires that the water 

c1ruw tcst be conduct cd with u!! 

elpctr:cal p'ower or fuel to thc heatin!! 

clem('nt~ or main burner interrupted to 

prev!:nt thf!ir operation. Section 3.7 

further reqlliff!s that the elapsed time 

from the start of the test until the first 

I·hf'rmostatllr.ts to operate the hentiri)! 

• ·I .. rnpnts or m.lin burner be reco~ded. 

The contrlhution of recuverv rate tu the 

first hour rnting measure wi'lI be 

calculat('d over thr. period of time of one 

hour minus this el;lpscd time. Thus. the 

c:.llculatrd recovery rate con!ribution 

term will account for tlll of the water 

thilt could be hf'ated by a watrr heater 

OVf:r the one hour time bnse of the first 

hour ratin)! ml'a~ure whilp the rf's'ults of 

!he wuter druw tf'~t will atcount for 

onlv the contribution of a wilter heHter'~ 

r.i'l;abilit'; to deliver hot w;;!cr frem 

~toru!!f'. Summin)! these two terms to 

yield lir~! huur r:lting will Rccount for all 

~f the hot wilfer that could p("~lbly be 

·1~lin'rt'd by f\ wiltf'r h"ilter o"f'r it one 

h'lUr peri"'f. 

h H'ctl'r drow tc.ot t"mp('ra!lIN~ drop. 

TW(l cC)mm('nt~ w('re mildr concerning 

the qpecificntion in Ihl' proposed wRtf'r 

draw test of a 4O"F outlet water 

temperature drop. Both commenters 

were concerned that the specified 

temperature drop was excessive and 

would lead to inflat~d values of first 

huur rating for water heaters which. in 

tum, could lead com;umers to purchase 

water heaters of insufficient capacity to 

satisfy their needs. One commenter 

remarked that a 20"F temperature drop 

specification would be more appropriate 

for the water draw test in light of 

recommendations being mad" to 

consumers to lower their water heuter 

thermostats to as low as 120"F. It was 

clilimed that consumers who operate 

their water heaters at these 

recommended thermostat settings will 

run out of usable hot water well before 

incurring a 40"F outlet water 

temperature drop but in most cases not 

before incurring a 20"F outlet 

temperature drop. 

The commenters are of the opin,ion 

that significantly different first hour 

rating water draw test r':!sults will be 

obtained if instead of specifying 40'f' as 

the outlet water temperature drop. a 

, smaller temperature drop is specified. 

DOE does not share this opinion. DOE 

finds that, for current water heilter 

designs. an outlet water temperature 

drop specification of 4Q"F will yield 

water draw test results only slightly 

grealer than those that would be 

obtained using a 20'F temperature drop 

specification. This is because current 

water heater designs inhibit dilution oi 

the stored hot water with the incoming 

cold water when subjected to a water 

draw. Thus. when subjected to the water 

draw test. these designs of water 

heaters exhibit a relatively constant 

outlet water temperature or an outlet 

wiltrr temperature which falls off only 

verv slowlv until most of the hot water 

hilS' been ~ithdruwn at which time there 

is il rllpid elrop of more than 40'F . 

While DOE dues not agree with the 

cornmenters' contention. i.e .. that the 

outlet water temperature drop 

specification of the first hour ratir.g 

wilter draw test has a signii'icant effect 

on the res !.I Its of the test. DOE dol'S nnd 

merit in the recommendation that 20"F 

be specified as the outlet water 

temperature drop for this test. Should a 

water heater manufacturer introduce a 

new desi)!n of water heater which does 

not inhibit dilution of the stored hot 

water with thr incur.ling cold water 

when subjected to a w:lter draw. 

conduct in,:; the W:,t(,T draw trst using 

;'fl'F ilS the outlet w.lter temperature 

drop spf'ciliciltiun Will ,ridd a more 

r.~prrsf'ntati .. e first hour ratin~ th:ll1 that 

which would have beer. determined had 

40'F been used a~ the cat!e! water 

temperature drop specification. By 

today's rule, section 3.7 of the test 

procedures for water heaters specifies 

20"F as the temperature drop for the first 

hour rating water draw test. 

c. Impact on water heater utility. A 

commenter exprcssed concern that the 

proposed first hour rating water draw 

test wouid encourage manufacturers to 

produce water heatcrS which do not 

maintain a relatively constant outlet 

water temperature when subjected to a 

water draw. The commentcr remarked 

that. through widely recognized industry 

standards. the water heater industry has 

encouraged water heater designs thOat 

can deliver the major portion of a water 

heater's storage capacity at a relatively 

constant outlet water temperature 

nearly equal to .the initial outlet water 

temperature when subjected to a water 

draw. The commenter pOinted out that 

the utility of such designs is that 

consumers can enjoy a relatively 

constant water temperature for personal 

applications. e.g., bathing and 

showering. without having to 

continually adjust the hot and cold 

water flew rates to account for 

fluctuations in the hot water supply 

temperature. The commenter remarked 

that DOE's proposed rule would 

adversely affect this utility. By not 

accounting for the energy associated 

with the water withdrawn from the 

water heater. the commenter pointed out 

that for a given water heater design 

more favorable results could be 

obtained with the proposed test if it 

were possible to modify the design of 

the water heater to cause the outlet 

water temperature to drop orr more 

quickly during the course of the water 

draw. It was pointed out that. all other 

things bein~ equal. the amount of water 

that could be withdrawn from a water 

heater which is capoble of maintaining a 

relatively constunt outlet water 

temperature will be less than the 

amount of water that could be 

withdrawn from a water heater which 

induces diiution of the storl'd hot waler 

with the incoming cold water (Le., in 

such a fashion that the ouilet water 

temperature would fall gradually 

through the temperature drop specified 

for the proposed first hour rating water 

draw test). A !;rcatcr total volume of 

water could be wi!hd!awn from the 

wilterheiltcr in the ):i:ter case because a 

si):nificant amount of the incoming cold 

water would be withdrawn uS a result of 

dilution. In Ihe fL'rr.ter casl!.vcrv little 

coldwater wou!d be Withdraw:; in 

Ilddition 10 the stn,'eel hot Willer 

withdrawn. Further. the great~r the 

outlet water tt:tr:;.>erature drop specified. 

the greater the "mount nfcold wiltl'r 
Federal Register / Vol. 44. No. 175 / Friday. September 7, 1979 / Rules and Regulations 52637

that could be withdrawn in the latter designs which permit such dilution, this First hour rating is intended as a

case, and the greater the disparity new approach will yield results measure to be used to properly size a

between the results of the first hour significantly lower than the results that wate, heater to a particular application.

rating water draw tests for the two the proposed test method would have The procedure for sizing the water

different water heater designs. yielded. heater involves making an estimate of a

Changing the outlet water temperature This new approach has been reasonable "worst case" hot water

drop specification for the first hour incorporated in the test procedures for demand that would occur over a one

rating water draw test from 40'F to 20'F water heaters by modifying section 3.7 hour period and selecting a water heater

lessens the magnitude of the problem to require that the outlet water with a first hour rating of nearly equal

identified by the commenter but has not temperature be recorded at 15 second magnitude.

eliminated the source of the problem. intervals throughout the duration of the DOE finds that the five gallon per

When referencing industry standards first hour rating water draw test and by minute (plus or minus 0.25 gallons per

which encourage water heater designs modifying section 4,8 to multiply the minute) flow rate specification that was

which deliver hot water at a relatively actual volume of water withdrawn from proposed for the first hour rating water

constant temperature when subjected to the water heater during the first hour draw test is appropriate for the purposes

a water draw. DOE assumes that the rating water draw test by the mean of of using first hour rating to properly size

commenter was referring to. for gas the recorded values of outlet water a water heater to a particular

water heaters, section 2.14 of the temperature divided by the initial outlet application. Therefore, no change has

American National Standard for Gas water temperature. This approach been made to this specification in

Water Heaters. Volume I, designated accounts for the energy content of the today's final rule.

ANSI Z21.1O.1a-1978. and, for electric weter withdrawn from the water heater. e. Timing the water drawtest. A

water heaters. section 4.4. of the The frequent outlet water temperature water heater manufacturer proposed

American Nationa! Standard for readings can be used to trace how the that DOE allow the.duration of the first

Household Automatic Electric Storage- energy content of the water withdrawn hour rating wiater draw test to be

Type Water Hleaters. designated ANSI from the water heater changes with calculated by dividing the volume of

C72.1-1972. DOE is not aware of the time. Thus. the product of the mean of water withdrawn from the water heater

existence of a widely recognized the recorded values of outlet water during the water draw test by the

standard which encourages this type of temperature and the actual volume of product of the nominal water

design for oil water heaters. However, water withdrawn from the water heater withdrawal rate of five gallons per

since the first hour rating of a typical oil during the test is proportional to the minute and the conversion factor, sixty

water heater is primarily a function of energy content of the water. Dividing minutes per hour. The point was made

its high recovery rate rather than its this product by some reference that adoption of this suggestion would

small storage capacity. the effects of temperature. in this case the initial eliminate the requirement for timing the

dilution during the first hour rating outlet water temperature, yields the duration of the water draw test.

water draw test, if any, will have little equivalent amount of water which. at Changes to the test procedures made

effect on the first hour rating measure. that reference temperature, would have in response to comments discussed

DOE considered the approaches taken the same energy content. previously under "Impact on water

by these standards for possible These modifications to the proposed heater utility" require the use of a clock

application to the test method for test method result in a negligible during the first hour rating water draw

determining first hour rating. DOE found increase in the test burden associated test. DOE finds that nothing would be

that a test approach similar to the one with the proposed test method. gained by adopting the commenter's

taken bythe ANSI Z21.10.la-1978 d. Rate of hot water withdrawal. Two suggestion. It has not been adopted.

standard for gas water heaters could be commenters recommended using a three f. Using the results of the water draw

developed for the first hour rating water gallon per minute withdrawal rate for test for more than one basic model. One

draw test which would neither the water draw test. They contended commenter remarked that there are encourage nor discourage water heater that a three gallon per minute flow rate various models of gas and oil water

designs which induce dilution of stored is more representative of typical hot heaters which utilize essentially the

hot water with incoming cold water water withdrawal rates encountered in same tank and water inlet (dip tube)

when subjected to a water draw. The the home. The point was made that design but differ in power input rating.

approach prescribed today considers the industry standards specify a three gallon The commenter recommended that. in

energy content of the water withdrawn per minuteflow rate for testing water cases such as this. the manufacturer

from the water heater during the first heaters. To DOEs explanation that a should be allowed to conduct the water

hour rating water draw lest. It adjusts. five gallon per minute flow rate had draw test on one model of water heater

on an energy basis. the measured been specified in the proposed test and then calculate the first hour rating

volume of water withdrawn to an method in order to reveal whether or not for the other gas and oil water heaters

equivalent. or adjusted, volume of water the design of the water heater fostered which are of the same tank and water

of equal energy content that would have dilution of the discharge water, one inlet design but have different power

been withdrawn from the water heater if commenter remarked that DOE's Inputs. It was argued that DOE permits a the discharge water temperature had proposed test method would. by use of similar scheme for determining the first

remained constant at its initial value. the higher flow rate, exaggerate the hour rating of electric water heaters

For water heater designs which inhibit effects of dilution. with immersed heating elements.

dilution of the stored hot water with the DOE finds that it is not unusual for Because the water draw test was incoming cold water during the first hot water to be withdrawn from a modified in response to comments

hour rating water draw test. this new household water heater at rate on the previously discussed under "Full versus approach will yield results nearly equal order of five gallons per minute or more. partial testing". the requirement to

to the results that would have been Such a flow rate is typical of the hot- separately test basic models of water

obtained using the proposed test water fill demands of clothes washers heaters which differ only by the power

method: However. for water heater and dishwashers. input has been eliminated.

EE-RM-94-230 COMMENT 49N

Federol Register I Vol. 44. No. 175 I Friday. Septeinber 7 • .1979 I Rules and Rcgulotions 52637 

that could be withdrawn in the latter 

case. and the greater the disparity 

between the results of the first hour 

raling water draw lesls for the two 

different water heater designs. 

Changinllihe outlel water temperature 

drop specifica tion for the first hour 

roting water draw te~t from 40"F to 20"F 

lessens the magnitude of the problem 

identifil!d by Ihe commenter but has not 

eliminated the source of the problem. 

\\'hen referencing industry standards 

which enwurage wuter he,ater designs 

which dl?liver hot water at a relatively 

constant temperature when subjected to , 

a water draw. DOE assumes that the 

commeriter'was referring to. for gas 

water heaters. section 2.14 of the 

American ~a tional Standard for Gas' 

Water, Heaters. Volume I. designated 

A;-";SI 221.1O.1a-1978. and. for electric 

water heaters. section 4.4. of the 

".merican I'\aticina! Standard for, 

Hou~ehold Automatic Electric StorageType Water lIeaters. designated ANSI 

C72.1-Hl72. DOE is not aWl:lre,ofthe 

existence of a widely recognized 

standard which encourages this type oC 

design for oil water heaters. However, 

since the first hour rating ora typical oil 

wilter heater is primarily a function of 

its high recovl!ry rate rather than its 

small stor d~e capacity. the effects of 

dilution during the first hour rating 

wuter draw test. if any. will have little 

effect on the first hour rating measure: 

DOE considered the approaches taken 

by these standards for pos~ible 

upplicution to the test method for 

de!t?rmining first hour rating. DOE found 

that a test approach similar to the one 

taken by the A~SI Z21.10.1a-1978 

standard for gns water heaters could be 

de~'eloped for the first hour rating water 

draw test which would neither 

, encourll/le nor discourage water heater 

de~ign~ which induce dilution of stored 

hot wuter with incomin!! cold WAter 

, when ~lIbll?cted to a water draw. The 

approach prescribed today considers the 

ener!ly content of the water withdrawn 

from the wllter heater during the nrst 

hour ratinR water draw test. II adjl,lsts. 

on an I!nl!rRY hasi~. the measur,cd 

volume of water withdrawn to an 

equivalent. or adjusted. volume of wlltl'r, 

of ('Qu.d enp.rRY content that would have 

bl!en withdrawn from the water heater if 

the ui'Chargc wlilcr temperature had 

remained constant At its initial value. 

For water heater design!! which inhibit 

dilution of thl! stored hot water with the 

incominR cold water during the fint 

'hour rlltinll w(lter draw test. this'new 

apprunch will yield rellults nearly equal 

to thl: results thilt would have bpen 

obtainl!d u~inR the proposed tellt 

metitod: Howe\·er. for water heater 

designs which permit such dilution. this 

new approach will yield results 

Significantly lower than the results that. 

the proposed test method would have 

yielded. . . 

, This new approach has been 

incorporated in the test procedures for 

water heaters by modifying section 3.7 

to require that the outlet 'water 

temperature be recorded at 15 second 

intervals ,throughout the duration of the 

first hour rating water draw test and by 

modifying s~ction 4.8 to multiply the 

actual volume of water withdrawn from 

the water,heater during the. first hour 

rating water draw test by the mean of 

the recorded values of outlet water 

temperature divided by the initial outlet 

water temperature. This approach 

accounts for the energy con lent oC the 

wrter withdrawn Crom the water heater. 

The frequellt outlet water temperature 

readings can be used to trace how the 

energy content of the water withdrawn 

Crom the water heater changes with 

time. Thus. the product oC the mean oC 

the recorded values oC outlet water 

temperature and the actual volume of 

water withdrawn from the water heater 

during the test is proportional to the 

energy content of the water. Dividing 

this product by some reference 

temperature. in this case the initial 

outlet water temperature. yields the 

equivalent amount oC water which. at 

that reference temperature, woUld have, 

the same energy content. 

These modifications to the 'proposed 

test method result In a negligible 

increase inlhe lest burden associated 

with the proposed test mE!thod. 

d.R~te of hot water withdrawal. Two 

commenters recommended using it three 

gallon per minute withdrawal rate Cor 

the water draw test. They contended 

that a 'three gallon per minute flow rate 

is more. representative of typical hot 

water withdrawal fates encountered In 

the home. The point was made that 

industry standards specify a three gallon· 

per lTlinuteflow rat!! for testing water 

heaters. To DOE's explanation that a 

five gallon per minute flow rate had 

been specified in the proposed test 

method in order io reveal whether or not 

the design of the water heater fostered 

dilution of the discharge water. one 

commentei' remarked that DOE's 

proposed test method would. by use of 

the hillher flow rate. exaggerate the 

effects of dilution. 

. DOE finds that it is not unusual for 

hot water to be withdrawn fron: a 

household water heater at rate on the 

order of fivegaJlons per minute cr more. Such a flow rate is typical of the hot, 

wa.ter fill cemands of clothes ~'ashers 

and dishwashers. . 

First bour rating is intended a8 a 

mea8ure to be used to properly size a 

wate. heater to a particular application. 

The procedure Cor sizing the water 

heater igvolves making an estimate of a 

reasonable "worst case'~ hot water 

demand that would occur over a one 

hour period and selecting a water heater 

with a first hour rating of nearly equal 

magnitude. 

DOE finds that the five gallon per 

minute [plus or minus 0.25 gallons'per 

mInuteJ flow rate speCification that was proposed for the first hour rating water 

draw test is appropriate for the purposes 

of using first hour rating to properly size 

a water heater to a particular 

application. Therefore, no change has 

been IDade to this specification in 

today's final rule. 

e. Timing the waterdrow,test. A 

water heater manufacturer proposed 

that DOE allow the, duration of the first 

hour rating ~'ater draw test to be 

calculated by dividing the volume of 

water withdrawn Crom the water heater 

during the water draw test by the 

product of the nominal water 

withdrawal rate oC five gallons per 

minute and the conversion Cactor, sixty 

minutes per hour. The point was made 

that adoption of this suggestion would 

eliminate the requirement Cor timing the 

duration of the water draw test. . 

Changes to the test procedures made 

in response to comments discussed 

previously under"Impact on water 

heater utility" require the use of a clock 

during the first hour rating water draw 

test. DOE finds that nothing would be. 

gained by adopting the commenter's 

suggestion. 11 has not been adopted. 

{. Using the results of the water draw 

test for more than one basic mode/. One 

commenter remarked that there are 

various models of gas and oil water 

hea ters which utilize esseritially the 

same .. tank and water inlet (dip tube) 

design but differ in power input rating. 

The commenter recommenl!ed that, in 

cases such as this. the manufacturer -

should be allowed to conduct the water 

draw test on one model oC water heater 

and then calculate the first hour rating 

Cor the other gas and oil water heaters 

which areoC the 8ame tank and water 

. Inlet design but have different power 

"nputs. It was argued that DOE permits a 

similar scheme for detennlning the first 

hour rating of electric water heaters 

With !mmersed lieating elements .. 

Because the water draw test was 

modified in response tocommentll 

previously disf;ussed under "Full versus 

partial testing", the requirement to 

. separately test basic models of water 

~eaters w~ich differ only by Ihe power 

mput ha~ been eliminated. 
52638 Federal Register / Vol. 44. No. 175 / Friday. September 7. 1979 / Rules and Regulations

g. Recovery rote calculation. One DOE's proposed rule for the which would be withdrawn from the

commenter recommended that water determination of first hour rating shared -water heater following DOE's proposed

heater manufacturers be permitted to this approach but required that a water water draw test.

use the nominal or design power input heater be tested to determine the The fourth proposed formula would

rating for the heating elements or main amount of hot water that can actually be determine the first term of the first hour

burner of a water heater for calculating withdrawn from storage. The amount of rating quantity in the same fashion as

its recovery rate in all cases. not just in water that can be heated and made the third formula would for gas and oil

the case of electric water heaters as available by a water heater, the second water heaters but would use the value

proposed by DOE. The point was made term of DOE's first hour rating quantity. 0.90 in place of 0.95 for determining the

that this would present the power input was to be determined by taking the adjusted rated storage capacity of an

in nominal terms which the consumer product of the recovery rate of the water electric water heater. In this case, DOE

has recognized through the years. By heater and a period of time equal to one assumes that the commenter intended to

nominal or design power input rating. hour less the elapsed time of the water refer to storage capacity as rated in

DOE assumes that the commenter draw teat. accordance with the method specified in

intended for the rating which appears on For determining the first term of the section 25.1 of the American National

the manufacturer's nameplate to be first hour rating quantity, two of the Standard for Household Electric

used. These ratings usually appear in suggested formulas multiply a water Stoage-Tank Water Heaters,

rounded terms, e.g., 30,000 Btu per hour heater's actual storage capacity. designated ANSI/UL 174-19. This

for a gas water heater. determined in accordance with DOE's standard requires the actual storage

DOE allows water heater test procedures. by 0.90. The rationale capacity of an electric water heater to

DOEf acllows water hedsnat nper offered for this recommendation was be not less than 90 percent of the rated manufacturers to use the design power that a quantity of water equal to about storage capacity. raeings fothe immersed heating90 percent of the actual storage capactv A fifth proposal for predicting the first elements they install in electric water of a water heater would closely term of the first hour rating quantity heaters for calculating the recovery rate approximate that amount which would ould require w r ater eater

of an electric water heater because DOE be withdrawn from the water heater manufacturers to calculate the minimum

has found that it would be unnecessarily following DOE's proposed water draw amount of water that could theoretically

burdensome to require testing of all te st be withdrawn from a water heater to

models of electric water heaters to d d e th satisfy the water draw requirement of

determine actual power input. However, i ter b mul l ter section 2.14 of the ANSI Z21.10.1-1975 first term by multiplying a water since measurement of actual power heater's rated storage caacit b 0 standard for gas water heaters and

input for gas and oil water heaters is nd then multiplying the result b 0.9 section 4.4 of the ANSI C72.1-1972

already required by the test procedures e f th t " d strastandard for electric water heaters. In By use of the term "rated storage for water heaters, DOE does not find the case of gas water heaters, this

that use of the measured value in the capacity DOE assumes that the minimum amount of water would be

recovery rate calculation presents a commenter s refering to orage determined by multiplying the actual

problem. Finally, since recovery rate is c of the American National storage capacity of the water heater by

also a function of the recovery efficiency 0.60. In the case of electric water

,f a; water heater, and recovery a ar 1 . heaters, this minimum amount of water het, an reoverye i Volume i. designated ANSI Z21.10.1- would be determined by multiplying the efficiency is a measure determined by 1975. or section 3.8 ofmutiplying the Amecane

tl:sl ,ird aLfected by the power input of Ntionactal Stan ora ge capacity of the waer

thei witer heater tested, DOE finds that Automatic Electric Storage-Type Water h by 0.80 for water h eaters having

it is more accurate to use the actual an overall tank height greater than 36

power input and recovery efficiency of a eaters. designated ANSI C7y -1972. inches. or by 0.70 for water heaters

water walter heater as determined by testingy DOE is not aware of the existence of a having an overall tank height less than heater as, determined by testing widely recognized standard . or equal to 36 inches. No

for calculating the recovery rate of the i or equal to 36 inches. No

wateor hee erefore. DOE has not pecification for rating te storage recommendation was made concerning

adopted the cormefntr' n capacity for an oil water heater, how to calculate the first term of the

adopted thnecommnen ntrs however, since the specifications for first hour rating measure for oil water rating the storage capacities of gas and heaters.

4. Predictin, first hour rut,,'g by electric water heaters referenced above In the case of the suggestion that

colru/ion. Five different formulas for are identical. DOE has evaluated the water heater manufacturers use the hot

predicting first hour rating by suggested formula as if the rated storage water delivery requirements specified in

calculation were suggested by as many capacity for an oil water heater were industry standards to calculate the

commenters. All of the proposed specified in an equivalent fashion. The amount of water to use in place of the

formulas shared the approach of referenced standards specifythat the results of the water draw test for

tsumming two terms, the first term being actual storage capacity of a water determining first hour rating. DOE finds some large percentage of the tank heater must be within plus or minus five that gross underestimates may result.

capacity and the second term being the percent of the rated storage capacity. By DOE rejects this calculation method

product of the recovery rate of the water multiplying the rated storage capacity of because it would yield unreasonably heater and some period of time. The first a water heater by 0.95. as is done in the low results for some water heater

term was intended to predict the amount suggested formula, the minimum .designs based on the data considered

of hot water that could be withdrawn allowable actual storage capacity for a under this rulemaking. from storage on demand. The second water heater of a given rated storage Concerning the suggested calculation

term was intended to predict the amount capacity would be used to calculate the methods which would use the adjusted of water that could be heated and made first term of the first hour rating rated storage capacity of a water heater

available by the water heater over the quantity. This "adiusted" rated storage instead of its actual storage capacity. one hour period that is the time base of capacity term would then be multiplied DOE finds no merit in using the adjusted first hour rating. by 0.90 to account for amount of water rated storage capacity of a water heater

EE-RM-94-230 COMMENT 49N

52638 Federal Register I Vol. 44. No, 175 I Friday. Septemuer 7. 1979 I Rules and Regulations 

g. Recovery rote calculation. One 

commenter recommended that water 

heater manufacturers be permitted to 

use the nominal or design power input 

rating for the heating elements or main 

burner of a water heater for calculating 

its recovery rate in all cases, not just in 

the case of electric water heaters as 

proposed by DOE. The point was made 

that this would present the power input 

in nominal terms which the consumer 

has recognized through the years. Dy 

nominal or dc~ign power input rating, 

[JOE 1J~~UmCR thllt the commenter 

inlf'ntletl for the rating which appears on 

the manufacturer's nameplate to be 

usec.l. Thcse ratings usually appear in 

rounded terms, e.g., 30,000 Btu per hour 

for a gas water heater. 

DOF. allows ..... ater heater 

m,Jnufacturers to usc the design power 

ratin!:s for the immersed heating 

clements they install in electric water 

hcaters for calculating the recovery rate 

of an electric water heatcr because DOE 

hilS f01Jnd that it would be unnecessarily 

burr!,'nsoTlw to require testing of all 

models of electric watcr heaters to 

determine actual power input. However, 

since measurement of actual power 

input for !las and oil water heaters is 

already required by the test procedures 

for wilter heaters, DOE docs not find 

that use of the measured \'alue in the 

recovery rate calculation presents a 

problem. Finally, since recovery rate is 

also a f:.lnction of the recovery efficiency 

of a w,,:er heater, and recovery 

dfir:iencv is II measure determined by 

tr,st "lid ~ffected by the power input of' 

th,~ wllter heuter tested, DOE fi:1ds that 

it i~ more accurate to usc the actual 

power input and recovery efficiency of a 

water heater as determined by testing 

for cillculating the recovery rate of the 

water heater. Therefore, DOE has not 

adopted the comml'ntcr'~ 

rf'cornm!'ndd tion. 

4. Prpc/icling first hour ruling bX 

(;olr:!I/otiun. Fivc differt'nt formulas for 

predicting first hour raling by 

calculation were su~ested by a~ mony 

commenh~rs. AI\ of the proposed 

formulas shared the approach of 

summing two terms, the first term being 

some larlje percentage of the tank 

r::lpacity find thl> second term being the 

product of thl' recovery rate of the water 

hellter and some period of time. The first 

tcrm Wll~ intended to predict the amount 

of hot water that could be withdrawn 

from storage on demand. The second 

t .. rm was intended te predict the amount 

of WHtrr that could be heated and made 

Available by the water heater over the 

onc hour period that is the tiMe hose of 

first hour raling. 

DOE's proposed rule for the 

determination of first hour rating shared 

this approach but required that a water 

heater be tested to determine the 

amount of hot water that can actually be 

withdrawn from storage. The amount of 

water t~at can be heated aDd made 

available by 8 water heater. the second 

term of DOE's first hour rating quantity. 

was to be detennined by taking the 

product of the recovery rate of the wilter 

heater and a period of time equal to one 

hour less the elapsed time of the water 

draw teat. 

For determining the first term of the 

first hour rating quantity, two of the 

suggested fOI:mulas multiply a water 

heater's actual storage capacity. 

determined in accordance v.ilh DOE's 

test procedures, by 0.90, The rationale 

offered for this recommendation was 

that a quantity of wat.er equal to about ' 

90 percent of the actual storage capacity 

of a water heater would closely 

approximate that amount which would 

be withdrawn from the water heater 

following DOE's pro;>osed water draw 

test. 

A third formula would determine the 

first term by multiplying a wat'er 

heater's rated storage capacity by 0.95 

and then multiplying the result by 0.90, 

By use of the term "rated storage 

capacity" DOE assumes that the 

commenter is referring to storage 

capacity as rated in accordance with 

section 2.26 of the American National 

Standard for Gas Water Heaters, 

Volume I. designated ANSI Z21.10.1-

1975, or section 3.8 of the American 

National Standard for Iiousehoid 

Automatic Electric Storage-Type Water 

Heaters, designated ANSI C72.1-1972. 

DOE is not aware of the existence of a 

Widely recognized standard . 

specification for rating the storage 

• capacity for an oil water heater; 

however. since the specifications for 

rating the storage capacities of gllS and 

electric water heater!! referenced above 

Arc ideritical. DOE has evaluated the 

~ugl!ested formula as if the rater.! storllge 

capacity for an oil water hea:er were 

specified in an equivalent fashion. The 

referenced standards sp!:!cify.thilt t..'1e 

octual storage capacity of a wa:er 

heater must be within plus or minus five 

percent of the rated storage capacity, By 

multiplying the rated storage capacity of 

a water heater by 0.95, as is done in the 

suggested formula, the minimum. 

allowable actual storage capacity for a 

water heater of a given rated storage 

capacity would be used to calculate the 

!irst term of the first hour ratin~ 

quan!ity. This "adjusted" reted ~torage 

capacity term would then be multiplied 

by O.9'J to account for amount of water 

which would be withdrawn from the 

water heater following DOE's proposed 

water draw teat. 

The fourth proposed formula would 

determine the first term of the first hour 

rating quantity in the same fashion as 

the third formula would for gas and oil 

water heaters but would use the value 

0.90 in place of 0.95 for determining the 

adjusted rated storage capacity of an 

electric water heater. In this case, DOE 

assumes that the commenter intended to 

refer to storage capacity as rated in 

accordance with the method specified in 

section 25.1 of the American National 

Standard for Household Electric 

Storage-Tank Water Heaters, 

designated ANSI/UL 174-1977. This 

standard requires the actual !torage 

capacity of an electric water heater to 

be not less than 90 percent of the rated 

storage capacity. 

A fifth proposal for predicting the first 

term of the first hour rating auantity 

would require water heater' 

manufacturers to calculate the minimum 

amount of water that could theoretically 

be withdrawn from a water heater to 

satisfy the water draw requirement of 

section 2.14 of the ANSI Z21.10.1-1975 

standard for gas water heaters and 

section 4.4 of the ANSI Cn.1-1972 

standard for electric water heaters. In 

the case of gas water heaters, this 

minimum amount of water would be 

determined by multiplying the actual • 

storage capacity of the water heater by 

0.60. In the case of electric water 

heaters, this minimum amount of water 

would be determined by multiplying the 

actual storage capacity of the water 

heater by 0.80 for water heaters having 

an overall tank height greater than 36 

inches, or by 0.70 for water heaters 

having an overatt tank height less than 

or equal to 36 inches. No 

recommendation was made concerning 

how to calculate the first term of the 

( first hour rating measure for oil water 

heaters. 

In the cllse of the suggestion that 

water heater manufacturers use the hot 

water delfvery reqt:irements spl'cified in 

industry standards to calculate the 

amount of wllter to use in place of the 

result3 of the water draw test for 

determininR first hour rating, DOE finds 

that gross underestimlltes may result, 

DOE rejects this calculation method 

because it would yield unreasonably 

low results for some water heater 

designs based on the data considered 

under this rulemaking. 

Co~ccming the suggested c;1l1e:uiation 

methods which would u~e the adjusted 

rated stora!!e capacity of a water heater 

instead of its actunl storage capacity. ' 

DOE finds no merit in u~ing the adjusted 

rated storage capacity of a water he?ter 
Federal Register / Vol. 44. No. 175 / Friday. September 7, 1979 / Rules and Regulations 52639

in a calculation for which the actual rating for the purposes of developing a hour rating water draw test immediately after

rated storage capacity of the water formula for calculating first hour rating. a cutout by recording the hot water outlet

heater has already been determined by According to the proposed test method, water temperature, recording the time, and

to-st. Further, adoption of this suggested the time duration for calculating the withdrawhng water from the water eater

calculation method would penalize contribution of recovery rate to the first t.0h0.25 gallons per minute. Interatpte

ater heater manufacturers who rate hour rating measure is one hour minus electrical power to the heating elements or the storage capacity of their water the time duration of the water draw. For fuel to the main burner of the water heater to

heaters conservatively. DOE rejects the the purposes of the formula for prevent their operation during this test.

suggestion that the adjusted rated calculating first hour rating, this time Collect all of the water withdrawn from the

stor,iae capacitv of a water heater be period be be determined by dividing water heater during the test in a suitable

used to calculate first hour rating for the predicted quantity of water container for the purpose of determining its

these reasons, withdrawn from the water heater during weight at the conclusion of the test.

Common to all but one calculation the water draw. i.e 0.85 ties theAlternatively a water ow meter may be tthwate raw.iy of . th ters het used to measure the volume of water nM,.thod w;ag the conlanlinrli thJat the storage capacity of the water heater in withdrawn from the water heater direcitv.

result of the first hotr rating water draw gallons. by the product of the nominal Beginning IS seconds after the start of the

trst for a water heater would be nearly water withdrawal rate of five gallons test and at every subsequent 15second

eqlual to ninety percent of the actual per minute and the conversion factor. interval throughout the duration of the water

storage capacity or the adjusted rated sixty minutes per hour. Carrying out the draw, record the outlet water temperature.

storage capacity of the water heater. mathematics, this will simplify to 0.0028 For the purposes of this test. the maximum

'l'hte exception was the suggested times the storage capacity. Therefore. recorded temperature shall be referred to as ;c:lc:ulation method, discussed above. the second term of the formula for the initial outlet water temperature. T..

that would use the hot water defiver predicting first hour rating by Monitor the functioning of the water heater thermostats and record the time that a rTquirements spec:ifi]cl in industry calculation becomes the product of the thermostat on the water heater acts to

standards.) DOE finds that the data ri-covery rate of the water heater and operate a heating element or the main burner.

submitted by the water heater industry the quantity. one minus the product of Continue the withdrawal of water until the

;and that generated by NBS 0.0028 and the storage capacity of the outlet water temperature drops to a value

su'bstantiates the commcnters' wafer heater. 20'F below the initial water temperature. at

coenention. For most water heaters the Section 4.8 of the test procedures for which time terminate the withdrawal.

trst data and the results of the suggested water heaters, prescribed today. Determine the weight of the water

c;lculation method agree within plus or presents the completeformula for withdrawn, W. in pounds measured with-an

minus three percent. However, this data calculating first hour rating. error no greater than 2 percent. or the volume otinus,~~~~~~ i three.~~~~~ percent. .of .. water withdrawn. G, in gallons measured also reveals that this suggested 5., Miscllaneous. After careful with anerrorano . Gra e than s mpercent.

calculation method may overestimate consideration of all of the comments, Determine the arithmetic mean of the outlet

the results of the first hour rating water DOE has made some editorial and minor water temperature readings recorded. Ta,. in

draw te'st for some water heaters by as technical changes that were not 'F. Determine the elapsed time of the test

nmuch as six percent. discussed above and incorporated them prior to a thermostat on the water heater

In keeping with DOE's position that in the final rule prescribed today. acting to operate a heating element or the

the formula for predicting first hour C. Regulatory Anolysis Reviel. main burner. t, in hours measured with an

rating to be included in the test The proposed rule has been reviewed error no greater than 2 percent. If a procedires for water heaters should in accordance with Executive Order thermostat on the water heater does not act

yield results which agree closely with 12044 and DO Order 2030 Fromheaing element or the main .12044 nd DOE Order 2030. From the burner within one hour after the start of the

the results that would le obtained regulatory analysis performed, it was test the test is to be terminated and t.

through testing but which are unlikely to determined that the proposal was expressed as one hour.

exceed such test results. DOE has significant in nature but did1

not have

adjusted the commenters' suggested maorimpacts to manufacturers and 2. Appendix E to Subpart B of Part 430

formula for calculating the results of the consumers (imposing annual economic is arnded by adding a new section 4.7 consumers (imposing annual economic to read as follows: first hour rating water draw test to yield costs of S100 million or more).

results six percent lower. This was 4.7 Recovery rate.

arcomplishIed by revising the formula nerg Policy andConeat . 4.7.1 Recoery rte for gcs and oil a.er .q-,, lea. - -as amended by Pub. L.95-:619. from 0.90 times the actual (or adjusted Depar.ment er For gas or oil water heater.

rated) storage capacity of a waler heater . 95-.) calculate the recovery rate. R. expressed in

in gallons. to 0.85 times the actual gallons per hour and defined as:

storage capacity of a water heater in In consideration of the fore8Oing, Part storage capacity of a water heater 430 of Chapter II of Title 10. Code of R = P x Er

llThe The comments comments which which pertained pertained to to the the Federal rtb Regulations ,efctvOtorgT-is amended as set k XAT

forth below. effective October g. 1979. 5 proposed method for calculating the

amount of water that could be heated Issued in Washington. D.C. August 30. whereand made available by a water heater 199.-k ;s defined in section 4.1.1.

over the one hour period that is the time Maxine Savitz. AT. is as defined in section 4.3.

base of the first hour rating measure. the Deputy Assistant Secretary. Conservation E, is as calculated in section 4..1.

second of the two terms of each and Solar Applications. P=power input to the burner, determined in

suggested formula for predicting first 1. Appendix E to Subpart B of Part 430 accordance with section 3.2.1. expressed

hour rating by calculation. were is amended by adding a new section 3.7 in Btu per hour.

addressed in the preceding section. The to read as follows: 4.7.2 Recovery rote for electric water

determinations made in response to 3.7 Firs herrati aers. For an electric water heater.

these comments apply here as well. Establish normal water heater operation with

As mentioned previously. DOE has the maximum mean tank temperature within

followed the approach of the proposed the range specified in section .6 and with all

test method for determining first hour air eliminated from the tank. Begin the first

EE-RM-94-230 COMMENT 49N

Federal Register I Vol. 44. No. 175 I Friday. September 7. 1979 I Rules and ~egula:tions 52639 

in a calculation for ..... hich the actuill 

rated stora!!e capilcity of the water 

heilter has already heen determined by 

\I'~t. Further. adoption of this suggested 

calculation method would penalize 

.... ater heater manufacturers who rate 

the storage capacity of their water 

h.!aters conserliatively. DOE rejects the 

~uggl~stion that the adjusted rated 

sturage r.apac:ity of a water hcat<:!r be 

l!sed to ,calculate first huor'rating fur 

t!wse reilsons. , 

Commun to all but onc calculatiun 

rii,·thod wa~ Ihl' I;onlenti'm th'lt the 

f"Hllit of th~ first h,,'ur ratin!! wilter draw 

'I'st for a ..... i1ler heater would be ncarly 

I·qual to ninety perr.lmt of the actuar 

storage capacity or the adjusted rilted 

storage capacity of the water heilter: 

{Th" eXCl'ption was the s(i)otgcsted 

calculati()nmethod. dIscussed above. 

that wuuld usc the hot water dciivc:v 

r'~quir!'mcnts spr!r:ifj'!d in industry' . 

s'anJards,j UOE finds that the data 

"ubmith.d by thc water hcatrr industry 

and that generated hy :-';IlS 

s!:bstanliillL'~ the wmmcnters' 

(;Imtention. 'For most water h!.aters the 

tl~st dat., and the results of the suggested 

r.alwlution method agree within plus or 

'minus,thr('c percent. However. this data 

a!sl) rr!vpals thaI this sUAAcsted 

calr:ulatior. method may O\'erestimate 

thl! rpsults of thr. first hour rating ..... ater 

draw test for some water heaters by as 

much as ~ix percent. 

In keepin!! with DOE's position that 

the formula for predicting first hour 

ralin!! to IJI' included in the test' 

rJroc;l!dljrl~.~ for wiltpr heaters shoulil 

yidd reRults which ugrec cloSI!ly with 

the rl'sults that would he ohtained 

throu!!h te~ting but which are unlikely to 

cxr.r.r.d such test results. DOE has 

adjusted the commenlers' suggested 

.formuln for calculatin!! the results of the 

first hour rating water draw test to yield 

Tl!sults six percent lower. This was 

nn;omplished by revisinR the formu!a 

from 0.00 times the actual (or adjusted 

rated) sloTa!(e capacity of a water healer 

in RlIllons. to 0.85 times the actuill 

slorage capacity of a water heater in 

gallons. 

The comments which pertained 10 the 

proposed method for calcu!ating the 

amount of wilter th;Jt could be hedted 

IIntl made availilble by a water hellter 

o\·p.r the one hour period that is the time 

bllse of the first hour rating measure. the 

second of the two terms of each 

sllAAested formula for predictins first 

hour ratins by calculation. were 

addrp.ssed in the preceding seclion. The 

determinations made in response to 

these comments apply here as well. 

As mentioned previously. DOE has 

followed the approRch of the proposed 

lI'st method for determining first hour 

rating for the p;Jrposes of developing a 

formula for calculating first hour rating. 

According to the proposed lest method. 

the time duration for calculating the 

contribution oE recovery rate 10 the first 

hour rating measure is one hour minus 

the time duration of the water draw. For 

the purposes of the formula for 

cilkulatir.g first hour rating. this tiI:1e 

period can be determined by dividing 

theprcdicted quantity or water 

withdrawn from the water heater durinS 

the water draw. i.e .. 0.85 times tl-.e 

storage capacity of the waler heater in 

!!illlOIlS. by the product of the nominal 

water ..... ithdrawal rate of five gallons 

per minute and the conversion factor. 

sixty minutes per hour. Carrying out the 

ma:hematlcs. this will simplify to 0.0028 

limes the storage capacity. Therefore. 

the second term of the formula for 

predicting first hour rating by 

calculation becomes the product ofthe 

r;'covery rate of the wilter heater and 

the quantity. one minus the product of 

0,002" and the storage capacity of the 

waier heater. 

Sec!ion 4,8 of the test procedures for 

waler heaters. prescribed loday. 

presents the complete formula for 

cdcu(aling first huur rating. 

5. Miscpllaneous. After carefui 

consideration of all of the comments. 

DOE has made some editorial and minor 

technical changes that were not 

discussed above and incorporated them 

in the final rule prescribed today. 

C. Regulatory Analysis Re~·ielV. 

The propos~d rule has been reviewed 

in accordance with Executive Order 

12044 and DOF. Order 2030. From the 

regulatory analysis performed. it ..... as 

determined that the proposal was 

significant in nature but did'not have 

major impacts to manufacturers and 

consumel'9 (imposing annual economic 

costs of $100 million or more). 

(f.ncI'RY Policy and Consen/ahon Act. Pub. L. 

9-1-16.:1.85 amended by Pub. L. 9!Hi1!/: 

Depnrtment of F.nergy Organization ".:1. Pub. 

L.9S-91.) 

In consideration of the foregoing. Part 

430 of Chapter II of Title 10. Code of 

Federal Regulations is amended.as set 

forth below. effective October 9. 1979. 

IS5u"din Washinglon. D,C .. Aullusl 30. 

1979. 

Maxine Savitz, 

V"puty Assistant Secretary. Conser.ation 

f1nd Solar Applications. 

1. Appendix E to Subpart B of Part 430 

is amended by adding a new section 3.7 

to read as follows: 

3.7 First hour ratinll water draw tl'M. 

F.stHbli.h normal waler healer operation with 

the maximum mean tank tempera:ure within 

th .. ranlle specified in section l.6 and willi all 

air eHminatedJrom the tank . .Begin the first 

hour rat'lng water draw test Immediately after 

a cutout by recording the hot wat,er outlet 

water temperature. recording the lime. and 

withdrawing water from the water heater 

through the hot water outlet at a rate of 

5.0:tO.25 gallon8 per minute. Interrupt 

electrical power to the hea ling etemen ts or 

fuel to the main burner 01 the water h .. ater 10 

prevent their operation during this test. 

Collect all of the water withdrawn from the 

water heater during the test in a suitable 

container for the purpose of determining its 

weight at the conclusion of the test. 

Alternatively. a water flow meter may be 

used to measure the volume of water 

withdrawn from Ihe water heoter directtv, 

Beginning 15 seconds after the stilT! 01 th'e 

lesl and at every subsequent 15 "econd 

interval throughout the duration of the water 

draw. record the outlel water temperature. 

For the purposes of this test. the maximum 

recorded temperature shall be relerrt'd to iJS 

the initial outlet water temperature. To. 

Monilor the functioning of the watpr h'.'d:er 

thermostats and record the lime thaI a ther:nostat on the water heater acts 10 

operate a heating element or the main burner. 

Continue the withdrawal of water until the 

outlet water temperature drops to a value 

.. 20'F below the initial water temperature. ilt 

which time terminate the withdrawal. 

Determine the weight of the water 

withdrawn. \Y. in pounds measured with'an 

error no grealer than 2 percent. or the \'olume 

of water withdrawn. G. in gallons measured 

with an error no greater than 2 percent. 

Determine the arithmetic mean of the outlet 

water temperature readings recorded. T ... in 

OF. Dlltermine the elapsed lime of the test 

prior to a thermostat on the water heater 

acting to operate a heating element or the 

main burner. 't.. in hOUTS measured with an error no greater thun 2 percenl.lf a 

ther.nostot on the water heater do"s not act 

to operate a heatinll element or the mnin 

burner wlthin,one hour after the start 01 the 

tl!st. the test is to be terminated and I" , 

expressed as one hour. 

2. Appendix E to Subpart B of Part 430 

is anwnded by adding a new section 4.7 

to read as follows: 

4.7 Recovery rate. 

4.7.1 Rpcovery ratl' for gros ar.d oil",o:I'r 

heaters. For a gas or oil water heater. 

calculate the recovery rate. R. expressed in 

gollons per hour and defined as: 

where--

R = P X Er 

k XATS 

k ;3;';' defined in section 4.1.1. 

~T. i. as defined in section 4.3. 

E,. Is as calculated in section 4.1.1. 

P=power input to the burner. determined in 

accordance with section 3.2.1. expressed 

in Btu per hour. 

4.7.2 Recovery rate for electric water 

heaters. For an electric water heater. 

.. 
52840 Federal Register / Vol. 44, No. 175 / Friday. September 7. 1979 / Rules and Regulations

calculate the recurry rate. R. expressed in which. in characteristic operation of the

gallons per hour and defined as: water heater, are not energized

R Pi i 3,412/k412 E B simultaneously at any time. P shall he R = P x Er x 3,412 Btu/kWh taken as the design power rating of the

k x /T heating element in closest proximity to

T5 the hot water outlet of the water heater.

where- expressed in kilowatts.

k is as defined in section 4.1.1. 3. Appendix E to Subpart B of Part 430

AT, is as defined in section 4.3. is amended by adding a new section 4.8 E, is as calculated in section 4.1.2 for electrtc to read as follows:

water heaters with other than immersed

heating elements. or section 4.1.3 for 4.8 First hour rating.

electric water healers with immersed 4.8.1 Method for determining first hour

heating elements. rating. Except as provided in section 4.8.2.

P' P. power input to the heating elements. first hour rating shall be determined in

expressed in kilowatts. determined in accordance with section 4.8.3.

accordance with section 3.2.1 for electric 4.8.2 Options for determining first hour

water heaters wilh other than immersed rating. Until December 1. 1979. first hour

heating elements or section 3.2.2 for rating may be determined in accordance with

electric water heaters with immersed either section 4.8.3 or section 4.8.4.

heating elements. with the following 4.8.3 First hourrating deterr;ined by exception: For electric water heaters testing. Calculate the first hour rating. F.

with dual immersed heating elements expressed in gallons and defined as:

F X + [R x (1 - tc)] , or

F G x T + R x (1 -t)]

where- temperature readings recorded during the

R is as calculiated in section 4.7.1 for gas and first hour rating water draw test.

oil water healers. or section 4.7.2 for determined in accordance with section

electric water heaters. 3.7. expressed in 'F.

IW = weight of the water withdrawn from the T.=initial outlet water temperature recorded

water heater during the first hour rating during the first hour rating water draw

water draw test. determined in test. determined in accordance with

aiccol:rdinLce with section 3.7. expressed in section 3.7. expressed in 'F.

purnds. t, -elapsed time of the first hour rating water

d :- 8.25 pounds per gallon. the nominal draw test prior to a thermostat on the

density of water. water heater acting to operate a heating

C = volume of water withdrawn from the element or the main burner, determined

vwa;elr heater during the first hour rating in accordance with section 3.7. expressed

water draw test, determined in in hours.

ac:rordanrr with section 3.7, expressed 4.8.4 First hour rating determined tPy

gallons. calculation. Calculate the first hour rating. F.

T,. airithmetic mean of the outlet water expressed in gallons and defined as:

F - (O.85 x v) + J R x [ hour - (0.0028 hour x V)]

cIallon

where- for calculating the duration of the water

V is as defined in section 4.1.1. draw during the first hour rating water

R is as calculated in section 4.7.1 for gas and draw test. determined by dividing 0.85.

oil water heaters. or section 4.7.2 for as defined in this section. by the product

electric Water heaters. of the hot water withdrawal rate during

0n 8, - the constla.lt multiplier for calculating the T rst hour rating water draw test. five

the results of the first hour rating water gallons per minute. and the conversion

1draw test. falctor. 60 minutes per hour.

O.on2n hour/gallon = the constant multiplier IFR Dt w."- .- Filed 7" 8l:i .-1

BILLINO CODE I650-O1-M

EE-RM-94-230 COMMENT 49N

.. 

52640 Federal Register I Vol. 44. No. 175 I Friday. September 7. 1979 I Rules and Regulations 

calc"lute the reco\~ry r~te. R. expressed In 

jlililons pt'r hour Hud defined HS: 

R • p. x Er x 3,412 Btu/kWh 

It x ATS 

wherek is as defined in section 4.1.1. 

AT. IS as defined in section 4.3. 

E, is as calculated in section 4.1.2 (or electrlt: 

wHter heaters with other than immersed 

heatinR clements. or section 4.1.3 for 

electric water heaters with immersed 

heating el .. ments. 

p' "0 P. puwer inpllt to the he~tin!! clements. 

tlxprp.socd in kllowal!8. determined in 

IIccord,lIIr:e with section 3.2.1 f(Jr electric 

wntcr heaters wiJh other than immersed 

h"iltinR elements or section 3.2.2 [or 

electric water hellters with immerscd 

h""tin!! elernellts. with the fullowing 

",ception: For electric water heaters 

wilh dual immersed heating el('ments 

f x + 

f = + 

wh,,,,,-

R is as calculated in section 4.7.1 for gas lind 

oil waler heaters. or section 4.7.2 for 

"Icetric water heaters. 

W ~ weiHht of the ",uter withdrawn from the 

w.tler heater during the first hour ratin!! 

wntcr drllw test. determined in 

IIcc;"dance with section 3.7. expressed in 

pllllnds. 

d :-II.~;I pounds p~r Ritllon. the nominal 

den.itv of wat"r. 

G = volllm~ of watN withdraw~ from the 

wat", heater durin!! the iirst hour rating 

wa!f'r draw te~t. d .. tcrmined in 

au:ordance with section 3.7. e .... pre~sed 

M,dlon •. 

T .. ~ arithmetic mPlln (If thp outlet watl'r 

which. in characteristic operation of the 

water heater. are not energiz~d 

simultanp.lIusly ot any time. P' shall h(' 

tuken as the de~;l:n power rillinll of the 

heatin<! clement in clospst proximity to 

the hot watcr outlet of the water heater. 

expressed in kilowatts. 

3. Appendix E to Subpart B of Part 430 

is amended by adding a new section 4.8 

to read as follows:' 

4.8 First hOlJr rotinll' 

4.8.1 Method fordelermilling firsl hour 

raling. Excepl as proo:ided in section ~.B.2. 

first hour rating shall be dp.termined in 

uccordance with section 4.8.3. 

4.8.2 Options for determinin.~ .firs I hour 

rating. Until December 1. 1979. first hour 

rating may be determined in accordance with 

either section 4.8.3 or section 4.B.4. 

4.8.3 First hour rating determined by 

lesting. Calculate the first hour rating. F. 

expressed in gallons and defined as: 

x or 

x (1 - t

c )] 

temperature readings recorded during the 

first hour ritting water draw test. 

determined in accordance with $ection 

3.7. expressed in '1". 

T. = initial outlet water temperllture recorded 

during the first hour rating ,wllter draw 

test. determined in accordance with 

section 3.7. expressed in 'F. 

t, ~elapsed time of the firsl hOllr ratin!! wilter 

druw II'S: prior to a thermostat on the 

water heater acting to operate a heating 

element or the main burner. determined 

in accordance with section 3.7. expressl'd 

in hours. 

4.8.4 First hour ratinil dctermined n.l· 

colcu/otion. Calc:ulale the first hour ratin!!. F. 

expressed in Malians and defined as: 

'f'~ (O.BSxVI + {R x [1 hour - (0,0028 hour x VI] t 

gallon f 

wher,,-

V i' a~ !leflnrd in sl'r:tion 4.1.1. 

R is as calcul"ted in section 4.7.1 for I!nS and 

oil wutl'r h'!rltcrs. or section 4.7.2 for 

el!'etric wiltpr hrate",. 

n R:t ~ the COIlSlilP.l multiplier for'cn1culating 

thl' r ... ult~ of the first hour rntinp. water 

tlr"w test. 

n.()()~n hour/Rallon =' the r:on~tant mllitipli~r 

for clllcu\ilting Ihe dumtion of the Willer 

draw during the first hour rating Witter 

draw test. determined by dividing 0.85. 

as defined in this secliun. by the product 

of the hot water withdrawal rate during 

the fir~t hour r::.ting water dmw test. five 

!!nllpns pl'r ",inule. and the conversion 

factor. 60 minutrs per hour. 

(fR £>.oc. ~~ f.lrd~:"Ct: 8 . .4:'1 ".~I 

8'I.LINO COOf: 6450-01-11